Chemistry Homework Questions & Answers Archive

Which solutions have the same molarity? Check all that apply. Solutions E and F Solutions C, D, and E Solutions C, D, and F Solutions A and F None of the above

(NH4)3PO4

Which of the following molecules will have dipole-dipole forces as the strongest intermolecular force? Choose three. CO BF3 NCl3 CO2 HF CH2F2

Which is a recommended step for your organization's procedure for handling a large chemical spill? A Clean up the spill B Do not let employees evacuate C Do not secure the area D Notify the emergency coordinator

Which statement is not part of Dalton's atomic theory? Certain groups of elements have similar properties. Atoms combine in simple whole-number ratios to form compounds. All atoms of a given element have the same mass and other properties. Each element is composed of indestructible particles called atoms.

Question 10 2 pts How many electrons would be expected in the outermost electron shell of an atom with atomic number 13 ? 1 6 3 4 2

ITEM II. Desarrollo ( 12 pts ). 9,0 g de agua líquida a 50°C 1 atm se calientan hasta obtener vapor de agua a 100°C y 0,5 atm a través de los siguientes procesos reversibles consecutivos: Calcule: a) El calor q en cal para el proceso A (2 pts) b) El trabajo (w) en cal para el proceso B (2 pts) c) ΔU en cal para el proceso C ( 2 pts) d) ΔH en cal para el proceso B(2 pt) e) ΔS en cal / K para el proceso C(2 pts) f) ΔG en cal para el proceso B(2 pts) Considere: T(K) = °C + 273; masa molar 18 g / mol ; Cv m = 1,5 R ; R = 1,987 cal mol^-1 K^-1; Cagua(1) = 1 cal g^-1 K^-1 ; ΔHvap = 540 cal g^-1

Write the chemical formula for this molecule:

Identify the most appropriate method to measure the mass of a sample of white powder. Select the single best answer. Place a weighing vessel on the balance and tare the balance. Then add the sample of white powder to the weighing vessel and record the mass. Place the weighing vessel on the balance and add the sample of white powder to the weighing vessel. Tare the balance and then record the mass. Place the sample of white powder on the balance and record the mass. Place a weighing vessel on the balance, add the sample of white powder to the weighing vessel, and then record the mass. Tare the balance. Then place a weighing vessel on the balance. Add the sample of white powder to the weighing vessel. Record the mass.

Question 8 Sodium Fluoride is a colorless or white compound often used as an insecticide and in toothpastes to prevent tooth decay. After sodium (Na) binds to fluoride (F), what charge is it left with? Sodium -10 -1 +11 +1

For each pair of compounds listed, check the box next to the one with the higher boiling point. compounds higher boiling point CI4 0 CBr4 (Circle) GeCl4 GeF4 (Circle) SiH4 (Circle) SiI4 (Circle)

MISSED THIS? Read Section 3.4. You can click on the Review link to access the section in your eText. Part A Classify each of the following compounds as ionic or molecular. Drag the appropriate compounds to their respective bins. Reset Help CF2C CO KMnO4 NI3 Cr2O3 Molecular Ionic Submit Request Answer Provide Feedback

SiO2(s) + C(s) → Si(s) + CO(g)

Complete the table below, classifying each element as an alkali metal, alkaline earth metal, transition metal, halogen, or noble gas. Symbol element name Family Name/Group# Is it metal, nonmetal, or Mg Si No family name, but 4A or IVA Br sodium Ni neon

What is the energy of the reactants?

Next, the chemist measures the volume of the unknown liquid as 0.577 L and the mass of the unknown liquid as 728 g. Calculate the density of the liquid. Be sure your answer has the correct number of significant digits. g . cm^-3 Given the data above, is it possible to identify the liquid? - yes - no - tetrahydrofuran - acetone - dimethyl sulfoxide - glycerol - pentane

Which element in hydrochlorothiazide, C7H8ClN3O4S2, has the greatest mass percentage? A carbon B chlorine C nitrogen D oxygen

Which type of bonding is never found in elements? A covalent B ionic C metallic D van der Waals' forces

You may have observed that rubbing alcohol (isopropyl alcohol) evaporates more easily than water. This indicates that the normal boiling point of water is higher than that of rubbing alcohol. Which of these two substances possesses stronger attractive forces between molecules? Briefly explain your answer.

Construct the expression for Ka for the weak acid, HPO4^2-. HPO4^2- (aq) + H2O(l) ⇌ H3O^+ (aq) + PO4^3- (aq)

Conclusion In your own words, DEFINE atomic mass and describe how to calculate it. How is it different from mass number? Explain how carbon's mass is 12.0108 , yet its mass number is 12.

When heated, lithium reacts with nitrogen to form lithium nitride: 6 Li(s) + N2(g) -> 2 Li3 N(s) Part: 0 / 2 Part 1 of 2 What is the theoretical yield of Li3 N in grams when 12.8 g of Li is heated with 34.9 g of N2? Be sure your answer has the correct number of significant digits. g

Pair of Functional Groups Similar IR Expected for: Differentiating IR Expected for: aldehyde carboxylic acid C=O stretch 1700 cm^-1 Very broad H-O stretch for acid only at 3600-2500 cm^-1 alcohol ether, both with 3 carbons alkane alkyne, both with 3 carbons alkane alcohol, both with 3 carbons ester ketone

9. Modelo en que una empresa transmite a otra una serie de conocimientos, asistencia e imagen comercial a cambio de una tarifa: a) Licencia de uso b) Transmisión de marca c) Franquicia d) Know how

How many moles of propane (C3H8) are present in 20.0 g of propane? (molar mass of C3H8=44.01 g) (A) 4.01 g (B) 18.01 g (C) 36.02 g (D) 54 g (E) 0.454 g

Indicar a qué elemento del patrimonio (activo, pasivo o patrimonio neto) corresponde: Servicio de Gas Valores recibidos de terceros (cheques) Costo de la mercadería vendida Préstamo del Banco de la Nación Argentina a pagar Sueldos a Pagar Saldo a pagar de IVA Materia Prima para producción Venta de mercadería Anticipos de sueldos Capital Social

At label 1 on the curve the predominant form of His is His^2- is - At label 2 on the curve the average net charge of His is -0.5 - At label 3 on the curve His is at its greatest buffering capacity - At label 4 on the curve pH=pKa of the carboxyl group - At label 5 on the curve histidine's carboxyl group is completely titrated with OH^- - At label 6 on the curve the predominant form of His is His^1- is -

Calculate the mass of forsterite (Mg2SiO4) that contains a million (1.000 x 10^6) magnesium atoms. Be sure your answer has a unit symbol if necessary, and round it to 4 significant digits.

83. What is the amount, in moles, of each elemental sample? MISSED THIS? Read Section 2.9; Watch KCV 2.9 a. 11.8 g Ar c. 26.1 g Ta b. 3.55 g Zn d. 0.211 g Li 84. What is the mass, in grams, of each elemental sample? a. 2.3 x 10^-3 mol Sb b. 0.0355 mol Ba c. 43.9 mol Xe d. 1.3 mol W 85. How many silver atoms are there in 3.78 g of silver?

Classify each observation according to the order of reaction it describes. Zero-order reaction A plot of the concentration of the reactant versus time yields a straight line. First-order reaction The half-life of the reaction is independent of the initial concentration. A plot of the natural log of the concentration of the reactant versus time yields a straight line. Answer Bank As the initial concentration of the reactant increases, the half-life of the reaction becomes shorter. The rate constant has units of M · s^-1. The rate constant has units of M^-1 · s^-1.

A sample of a "suboxide" of cesium gives up 1.6907% of its mass as gaseous oxygen when gently heated, leaving pure cesium behind. Determine the empirical formula of this binary compound.

How many grams of gold (Au) are there in 93.37 moles of Au? Be sure your answer has the correct number of significant digits. g Au × 10^1

A compound containing Na, C, and O is found to have 1.06 mol Na, 0.528 mol C, and 1.59 mol O. What is the empirical formula of the compound?

Use the mass spectrum of lead to estimate the atomic mass of lead. Estimate the mass and percent intensity values from the graph to three significant figures. The peak representing Pb-204 has a percent intensity of 2.70%; the peak representing Pb-206 has a percent intensity of 46.0%; the peak representing Pb-207 has a percent intensity of 23.1%; and the peak representing Pb-208 has a percent intensity of 22.6%. Express your answer to three significant figures and include the appropriate units.

Scroll down to open a Hint. The metal used in this experiment is tin (Sn) which has a density of 7.283 g / mL near room temperature. Use 7.283 g / mL as the true value for density of Sn and calculate the absolute error and relative error for density determined for each sample. Report absolute error values for A 3 in g / mL to the nearest 0.01 g / mL. Do not enter the unit. Report percent error values for A 4 in % to the nearest 0.01 %. Do not enter the % symbol.

Given a watery solution in which 1 / 1,000,000(1 × 10^-6) particles are free H+ ions, what will the pH be?

This shows five isomers of C5H10O2 . The two structures that would be hardest to distinguish by IR spectroscopy are

Draw a resonance structure that is a more significant contributor to the resonance hybrid than the one shown.

Suppose you are performing a titration. At the beginning of the titration, you read the titrant volume as 1.08 mL. After running the titration and reaching the endpoint, you read the titrant volume as 22.80 mL. What volume, in mL, of titrant was required for the titration?

Question 3 (10 points) If one can find the ratio of the number of moles of the elements in a compound to one another, one can find the formula of the compound. In a certain compound of copper and oxygen, CuxOy, we find that a sample weighing 0.7323 g contains 0.6896 g of Cu .

Solve for (x) in terms of (a, b), and (c: ax-3b=c) 1. (a(c+3b)) 2. (a(c-3b)) 3. ((c-3b)/a) 4. ((c+3b)/a)

tungsten: [Xe] 6s^2 4f^14 5d^4 inner electrons: 1s^1 2s^2 2p^6 3s^2 3d^10 3p^6 4s^2 4d^10 5p^6 outer electrons: 6s^2

17. Three moles of copper(II) sulfate, CuSO4, contains a. 4 b. 6.02 × 10^23 c. 1.51 × 10^23 d. 8 moles of oxygen. e. 12.04 × 10^23 f. 12 18. 0.400 moles of sucrose, C12H22O11, contains carbon atoms. a. 12 b. 6.02 × 10^23 c. 2.89 × 10^24 d. 5.02 × 10^22 e. 4.80 19. If 36 g of water is stored in a water bottle, how many grams of hydrogen are present? a. 1.0 g b. 2.0 g c. 3.0 g d. 4.0 g e. 8.0 g

Adding and Subtracting with Significant Figures Calculate the following to the correct number of significant figures. 0.157+0.16= 357.95-152= 1.030 x 10^-9 + 5.721 x 10^-8= Note: You can earn partial credit on this problem.

In the diagram of single beam photometer given below, identify the component that is not marked. Sample holder Monochromator Interference filter Absorption filter

Next, the chemist measures the volume of the unknown liquid as 0.577 L and the mass of the unknown liquid as 728 g. Calculate the density of the liquid. Be sure your answer has the correct number of significant digits. g . cm^-3 Given the data above, is it possible to identify the liquid? yes no tetrahydrofuran acetone dimethyl sulfoxide glycerol pentane

Find the mass of the thin bar with the given density function. ρ(x)=1+sin x ; for 0 ≤ x ≤ π/3 Set up the integral that gives the mass of the thin bar.

Atomic size decreases going from left to right within a period. True False

Name: Lab Partner: Experiment 7 Post-Lab Sheet Results Data (4 pts) - mass of crucible and cover: 27.5651 g - mass of crucible, cover and NaHCO3: 51.5510 g - mass of crucible, cover and product: 44.4523 g - theoretical yield of Na2CO3: - theoretical yield of Na2O: - mass of product: - identity of product: - % yield of product: (2 pts) Show how you calculated the theoretical yield of Na2CO3. Include units! (1 pt) Show how you calculated the % yield:

What is the chemical formula for the compound formed between scandium(III) and the chlorate ion? chemical formula: What is the chemical formula for the compound formed between scandium(III) and the sulfate ion? chemical formula:

15. Americium -242 is a beta emitter. Write an equation for this nuclear reaction and identify the product nucleus.

The amount of rainfall in the Amazon rain forest is what kind of variable? Discrete Continuous Categorical Qualitative

Question 1 2 pts Calculate ΔG° for the following reaction of ammonia with fluorine. 2 NH3(g) + 5 F2(g) → N2 F4(g) + 6 HF(g) Substance: NH3(g) F2(g) N2 F4(g) HF(g) ΔG° f(kJ / mol): -16.4 0 79.9 -275.4 179.1 kJ -179.1 kJ 1539.7 kJ -1539.7 kJ None of these choices are correct.

How does the glass get colored?

The compound below contains a functional group.

Identify the kind(s) of intermolecular forces that would occur between the solute and solvent in an isopropyl alcohol (which is polar and contains an OH group) solution. Check all that apply. dispersion hydrogen bonding ion-dipole dipole-dipole

What is the molar mass of CH4? (C = 12.01 g / mol, H = 1.008 g / mol) A. 1 g / mol C. 13.02 g / mol B. 4 g / mol D. 16.04 g / mol

If 52.68 g of carbon are contained in 64.08 g of a compound containing only carbon and hydrogen, then how many grams of hydrogen are contained in the compound?

There are four common oxoanions of iodine and two common oxoanions of nitrogen. Match the name of each ion to its formula. IO4- NO3- IO3- IO2- NO2- IO- iodide ion periodate ion nitrite ion iodite ion iodate ion hypoiodite ion nitrate ion

Balance the following equations: 1) 2 NaNO3+ PbO → Pb(NO3)2+ Na2 2) AgI+ Fe2(CO3)3 → FeI3+ Ag2 CO3 3) C2 H4 O2+ O2 → CO2+ H2 O 4) ZnSO4+ Li2 CO3 → ZnCO3+ Li2 SO4 5) V2 O5+ CaS → CaO+ V2 S5 6) Mn(NO2)2+ BeCl2 → Be(NO2)2+ MnCl2 7) AgBr+ GaPO4 → Ag3 PO4+ GaBr3 8) H2 SO4+ B(OH)3 → B2(SO4)3+ H2 O 9) S8+ O2 → SO2 10) Fe+ AgNO3 → Fe(NO3)2+ Ag

A Balancing Act * To indicate more than one unit taking part or being formed in a reaction, a number called a is placed in front of it to indicate how many units are involved. * To balance the previous equation, we can add a coefficient of 2 in front of NaOH . Now, check to see if the equation is balanced by counting the atoms below:

Question 12 (5 points) Complete each reaction as best as you can. + HOH -> H^+ a) b) c) d)

A. La energía libre al unirse los átomos de magnesio al ATP. B. La energía libre producida al romperse los enlaces covalentes que mantienen unidas a las enzimas con sus sustratos. C. La energía libre producida en la ruptura de los enlaces del ATP. D. La energía emitida al formarse las fuerzas de interacción débiles que se producen entre la enzima y su sustrato.

Specify the local electron geometries about the atoms labelled a-d. Unshared electron pairs affect local geometry and are included in the structural formula. For each atom enter one of the following: tetrahedral, square planar, trigonal planar, trigonal pyramidal, or linear. (a) (b) (c) (d)

HC==CH / a N N c :O: b=C :O: C6H5

What is the correct reading of the volume in the pictured buret? Make sure to report your reading with the appropriate significant figures. Select one: 17.4 mL 17.325 mL 18.7 mL 17.3 mL 17.32 mL 18.68 mL

Question #13: Objective 3.3 Calcium (20Ca) has 26 known isotopes, ranging from 35Ca to 60Ca. Using 5 of those isotopes: 35Ca, 40Ca, 41Ca, 42Ca, 52Ca Two of those listed above are stable and three are radioactive. Explain which isotopes you believe are stable and why, and which isotopes you believe are radioactive and why. (answering the why is the important part) Need at least 2 different reasons why. You don't need to state what radiation they will release (so the answer to this question will not be found looking up these isotopes on Wikipedia or the dynamic periodic table) Answer the above question in your Knowledge Check Answer Sheet Page 4 (make sure you include the symbol Ca in your explanation)

Balance the following equations and identify the type of reaction(4marks): - C2H6+O2 CO2+H2O 2 C2H6+7 O2 -> 4 CO2+6 H2O - Li+ O2 Li2O combustion 4 Li+O2 -> 2 Li2O synthesis - Al(NO3)3+SrCO3 Al2(CO3)3+Sr(NO3)2 2 Al(NO3)3+3 SrCO3 -> Al2(CO3)3+3 Sr(NO3)2 - NO2 NO+O2 Double displacement.

The following reaction has an equilibrium constant of Kp=2.26 x 10^4 at 298 K CO(g)+2 H2(g) ⇌ CH3OH(g) Calculate K'p for the following reaction: 3 CH3OH(g) ⇌ 3 CO(g)+6 H2(g)

Iron(III) sulfate is a(an) Ionic compound Molecular compound

What important discovery did Ernest Rutherford find about the atom in his gold foil experiment? Rutherford discovered protons and neutrons during the gold foil experiment Rutherford discovered the nucleus during the gold foil experiment Rutherford discovered electrons during the gold foil experiment Rutherford discovered neutrons during the gold foil experiment

Questão 4 / 4 413982 75 res Mapa de questões 4 Sem resposta Para cada substância, existe um diagrama de fases particular. Por mais que substâncias possam ter diagramas de fases similares, é difícil observar dois diagramas exatamente iguais, inclusive com as informações sobre temperatura e pressão. Nos diagramas de fase, existe um ponto conhecido como ponto triplo, onde a substância está Assinale a afirmativa correta A prestes a se tornar um fluido supercrítico. B em processo de condensação. C a mais próximo do zero absoluto possível. D nos estados sólido, líquido e gasoso ao mesmo tempo. E transacionando do estado sólido para o estado líquido.

What is the electron configuration for tungsten? A) 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^104p^6 5s^2 4d^10 5p^6 6s^2 4f^14 5d^6 B) 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^2 4d^10 5p^6 6s^1 4f^14 5d^5 C) 1s^2 2s^2 2p^6 3s^2 3p^5 4s^2 3d^10 4p^6 5s^2 4d^10 5p^6 6s^2 4f^14 5d^7 D) 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^2 4d^10 5p^6 6s^2 4f^145 d^7 E) 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^2 4d^10 5p^6 6s^2 4f^145 d 1/t

Which atoms could combine to form an ionic compound? Silver and calcium Sulfur and chlorine Silver and phosphorus Hydrogen and sulfur

The name of TiS2 is titanium sulfide titanium(II) sulfide titanium(IV) sulfide titanium sulfate titanium (il) sulfate

Answer the following for a Se atom. Include the sign of the charge of the ion even if it is positive and place it in front of the number. For example, enter -3 not 3 - or 3.

This chemical reaction is exothermic. High temperatures are usually not ideal for exothermic reactions. Look closely at the chemical reaction equation. Why do you think high temperatures are used in the Haber Process? What does increasing the temperature do to the reactant particles that would result in a higher product yield?

Determine the absorbance if the percent transmission is 68.6%.

Which of the following is a terpene? I II III IV

A sample of a substance with the empirical formula XBr2 weighs 0.4895 g. When it is dissolved in water and all its bromine is converted to insoluble AgBr by addition of an excess of silver nitrate, - XBr2 + 2 AgNO3 -> 2 AgBr + X(NO3)2 (a) Calculate the formula mass of XBr2. Formula mass XBr2= g mol^-1 (b) Calculate the atomic mass of X. Atomic mass X= g mol^-1

Glucagon increases blood glucose levels by stimulating - muscle cells to make glycogen - muscle cells to break down muscle glycogen - liver cells to break down liver glycogen - both liver and muscle cells to break down their glycogen stores

Multiple Select Question Select all that apply Chlorine typically forms an ion with a charge of -1 . Which elements below are likely to form ions with the same charge as chlorine? I F Mg K S Need help? Review these concept resources.

Convert 301 K to °F.

Of the following, which is the strongest base?

Compare the structures of the conjugate acids drawn in parts (a) and (b) of this problem, and determine which is more stable. Based on the stability of the conjugate acids, determine which base, ammonia or DBN, is the stronger base. Explain your choice. - Ammonia is the weaker base because it has the more stable conjugate acid. - DBN is the stronger base because both nitrogen atoms have delocalized lone pairs. - DBN is the stronger base because it has a resonance-stabilized conjugate acid. - Ammonia is the stronger base because it has the more stable conjugate acid.

Provide the correct IUPAC/systematic name for the following compound.

0. State the boiling point of water on the following temperature scales. (a) Fahrenheit (b) Celsius (c) Kelvin

H−is known as hydrogen hydride helium fluoride

Some polyatomic ions name chemical formula - - Ï] CO3^2- acetate anion NH4^+ ClO3^-

Question 16 2 pts Provided below are a variety of past environments in which chemical sedimentary rocks form. Match the name of the rock that would form with the environment in which the sediments and ultimately this rock would form. Limestone Coral Reef Chert Deep marine Travertine Hot Springs and Caves Rock Salt (Halite) Ancient Inland Seas

The stoichiometric coefficient of the product in a formation reaction must be 1 . Write a balanced chemical equation for the standard formation reaction of solid mercury(II) oxide ( HgO ).

Practice - Stoichiometry 1) In a chemical reaction requiring two atoms of phosphorus for five atoms of oxygen, how many grams of oxygen are required by 3.10 g of phosphorus? 2) What mass of sulfur must combine with aluminum to form 600 lbs .(272.4 kg) of aluminum sulfide?

Show reagents and experimental conditions to synthesize each compound from 1-propanol.

In regards to acute and chronic hazards, there are only two routes of exposure: injection and inhalation.

A reaction profile (not to scale) for the reaction NO + CO2 → NO2 + CO is shown below: Reaction Coordinate What is the value of the activation energy for this reaction? kJ Is this reaction exothermic or endothermic? What is the value of ΔE for the reaction? kJ

1. Write a complete reaction for the chain initiation step for the polymerization of Methyl Methacrylate using Benzoyl Peroxide as an initiator. 2. Use the above reaction product to write one cycle of the chain propagation step for the polymerization of Methyl Methacrylate.

The image contains a red circle representing the nucleus of an atom, with the notation 8p+ (protons), 8n0 (neutrons), and 8e- (electrons) inside. It also shows a light blue box resembling a user interface with icons or buttons marked with an "X" and a curved arrow symbol. write in notation

Multiple Choice Question Reaction of an alkene with the halogens Br2 or Cl2 will result in the addition of halogen atom(s) to the double bond C atoms, producing a(n) 1, alkyl halide 2, vicinal dihalide 1, hydrogen halide 2, geminal dihalide

Why is the ionization energy of Cl lower than F, but higher than that of S?

Match the receptor type with the usual type of hormone Nuclear receptors Cytoplasmic receptors Membrane receptors [Choose] [Choose ] usually bind membrane soluble hormones usually bind water soluble hormones [Choose]

A 9.112 gram sample of an organic compound containing C, H, and O is analyzed by combustion analysis and 11.56 grams of CO2 and 3.156 grams of H2O are produced. In a separate experiment, the molar mass is found to be 104.1 g / mol. Determine the empirical formula and the molecular formula of the organic compound. Enter the elements in the order C, H, O empirical formula = molecular formula =

When Benzoic acid (PhCO2H) is deprotonated it generates a resonance stabilized anion at which position within the aromatic ring relative to the carboxyl group? Enter all that apply. ortho meta para it is not resonance stabilized by the ring

Write the name for Mg(IO3)2.

Which of the following is the chemical formula for potassium nitrate? Select one: a. KNO3 b. KNO2 c. PNO2 d. PNO3

Module Two: Project Management Methodologies (Question 9/20) Question 9 Your Waterfall project team is gathering project records, analyzing whether the project was a success, collecting lessons learned from the team, and archiving project information. What are you doing? a monitoring and controlling the project work b integrating the project plan c closing the project d managing project execution e Leave blank for now. I'll submit my answer later.

Based on what you have seen, which is the best definition for an acid? a) Acids split into two molecules in aqueous solution b) Acids remove a proton from each water molecule c) Acids donate protons in aqueous solution d) Acids accept protons from water molecules

Which of the following kingdoms of Eukarya consists primarily of one celled organisms? Monera Plantae Protista Fungi Animalia

Question 2 of 14 Points possible: 1.00 Choose the best graduated cylinder to make each measurement in a single use. 36 mL of water Choose... 5.75 mL of a sucrose solution choose... 18.5 mL of a NaCl solution choose...

What do you think would happen to water and DNA if we exchanged all hydrogen bonds with other permanent dipole-dipole forces? a) DNA would become less stable. Water would boil at a lower temperature. b) DNA would become more stable. Water would turn to ice. c) DNA would hydrolyze into its monomers. Water would never freeze. d) DNA would become more stable. Water would boil at a higher temperature.

A reaction profile (not to scale) for the reaction 2 HI -> H2 + I2 is shown below: Reaction Coordinate What is the value of the activation energy for this reaction? kJ Is this reaction exothermic or endothermic? What is the value of ΔE for the reaction? kJ

A chemist must dilute 14.5 mL of 159 mM aqueous potassium dichromate (K2Cr2O7) solution until the concentration falls to 8.00 mM. She'll do this by adding distilled water to the solution until it reaches a certain final volume. Calculate this final volume, in liters. Be sure your answer has the correct number of significant digits.

Which of the following represents the number of the molecules, of the type indicated, is present as a reactant or product of the chemical reaction shown? a. Coefficient b. Subscript c. Symbol d. Product

C6H15N 1H NMR a= 6= 13C NMR

Since water molecules are polar, substances will easily dissolve in it, but substances will not dissolve in it.

Fill in the missing information: symbol atom or ion? check all that apply number of protons number of electrons --- --- --- --- In neutral atom, cation, anion Br^- neutral atom, cation, anion neutral atom, cation, anion 5 2

What is the empirical formula of acetic acid, HC2H3O2? A HCO B H2C4H6O4 C H2CO D CO2

The atomic number of an element is 15. What is the likely arrangement of the valence and core electrons in a neutral atom of this element? A. There are 3 valence electrons and 12 core electrons. B. There are 4 valence electrons and 11 core electrons. C. There are 5 valence electrons and 10 core electrons. D. There are 6 valence electrons and 9 core electrons.

If a projectile is launched vertically upward from the ground with an initial velocity of 50 ft per sec, then neglecting air resistance, its height s (in feet) above the ground t seconds after projection is given by s=-16 t^2+50 t. Which equation should be used to determine the time at which the height of the projectile reaches 20 ft ? Choose the correct answer below. A. 20=-16 t^2 B. s=-16(20)^2+50 C. 20=-16 t^2+50 t D. s=-16(20)^2+50(20)

Empirical formula from % composition (Step 1) Given that a compound X has the following percent composition: 40.00 % C 6.71 % H 53.28 % O That means that in a 100.00 g sample of compound X, you'd have type your answer... g of C type your answer... g of H type your answer... g of O type numbers into the boxes, watch your sig-figs and round correctly Empirical formula from % composition (Step 2) Given that a compound X has the following percent composition: 40.00 % C 6.71 % H 53.28 % O That means that in a 100.00 g sample of compound X, you'd have type your answer... mol of C type your answer... mol of H type your answer... mol of O use average atomic masses from ptable.com type numbers into the boxes, watch your sig-figs and round correctly

If the mix ratio for a certain chemical is 1:4 when it is mixed with water (chemical:water), how many gallons of water would be mixed with 1/2 half gallon of chemical?

The drawing below shows a mixture of molecules: Suppose the following chemical reaction can take place in this mixture: 4 HCl(g) + O2(g) → 2 H2O(g) + 2 Cl2(g) Of which reactant are there the most initial moles? Enter its chemical formula: Of which reactant are there the least initial moles? Enter its chemical formula: Which reactant is the limiting reactant? Enter its chemical formula:

Complete the table below by filling in the principal quantum number n and angular momentum quantum number I for each electron subshell listed. subshell principal quantum number n angular momentum quantum number I --- --- --- 4 f 3 s 6 d 2 p

4-brom

3. What does it mean to manipulate a variable? a. to hold extraneous variables constant b. to turn a potential cause on and off c. to measure the variable's effect on behavior d. to hold the potential cause constant

Classify each of the following reactions as one of the four possible types summarized in the lecture slides as: (1) spontaneous at all temperatures; (ii) not spontaneous at any temperature; (iii) spontaneous at low T but not spontaneous at high T; (iv) spontaneous a high T but not spontaneous at low T. a. N2(g)+3 F2(g) → 2 NF3(g) ΔHrxn°=-249 kJ ; ΔSrxn°=-278 J / K ΔHrxn°=460 kJ ; ΔSrxn°=-275 J / K ΔHrxn°=85 kJ ; ΔSrxn°=198 J / K

What is the heat of reaction? kJ / mol Is the reaction exothermic or endothermic? Exothermic Can you determine the activation energy? Yes, it's kJ / mol Can you determine the activation energy of the reverse reaction? No.

Please categorize the following. Arrhenius Base Lewis Base Possible answers H+ acceptor Electron pair donor Bronsted-Lowry Base ions in aqueous solution

Calculate the number of cations and anions in 4.32 g of Na2SO4.

Balance the following redox equation, assuming acidic conditions: HCOOH + MnO4^- -> CO2 + Mn^2+

Which of these elements is chemically similar to magnesium? Select one: a. calcium b. nickel c. iron d. sulfur e. potassium

You were instructed to add 1.0 mL out of 5.0 mL of an undiluted sample to 99 mL of sterile diluent. Instead, you add the entire 5.0 mL to the 99 mL . A.) What was your intended dilution factor? (2 points) B.) What was your actual dilution factor? (2 points) Show your work.

What is the molar mass of nitrogen gas? 28.0 g / mol 1.20 x 10^23 g / mol 14.0 g / mol 6.02 x 10^23 g / mol

밑변이 길이가 2/5 m 인 어느 평행사변형의 넓이 4 m^2 입니다. 이 평행사변형의 높이는 몇 m인가요? (4) 10 m (2) 10 1/2 m (3) 10 1/5 m (4) 11 m (5) 11 1/5 m

Some chemical compounds are listed in the first column of the table below. Each compound is soluble in water. Imagine that a few tenths of a mole of each compound is dissolved in a liter of water. The important chemical species that would be present in this solution are written in the second column of the table. Use the checkboxes to classify each compound. compound important species present when dissolved in water type of compound (check all that apply) --------- ionic molecular strong acid weak acid strong base weak base HCl H3O+, Cl-, H2O ○ ☐ ☐ 0 0 0 KOH K+, OH-, H2O ☐ 0 ○ 0 ○ 0 C2H5NH2 C2H5NH3+, OH-, C2H5NH2, H2O 0 ☐ ○ ○ ○ O HNO2 H3O+, NO2-, HNO2, H2O ○ 0 O 0 O 0

How many atoms of hydrogen (H) are present in 200 molecules of ammonia (NH3)? Express your answer numerically.

Keeping water clean. Keeping water supplies clean requires regular measurement of levels of pollutants. The measurements are indirect - a typical analysis involves forming a dye by a chemical reaction with the dissolved pollutant, then passing light through the solution and measuring its "absorbance." To calibrate such measurements, the laboratory measures known standard solutions and uses regression to relate absorbance and pollutant concentration. This is usually done every day. Here is one series of data on the absorbance for different levels of nitrates. Nitrates are measured in milligrams per liter of water. Nitrates: 50, 50, 100, 200, 400, 800, 1200, 1600, 2000, 2000. Absorbance: 7.0, 7.5, 12.8, 24.0, 47.0, 93.0, 138.0, 183.0, 230.0, 226.0. a. Chemical theory says that these data should lie on a straight line. If the correlation is not at least 0.997, something went wrong, and the calibration procedure is repeated. Plot the data and find the correlation. Must the calibration be done again? b. The calibration process sets nitrate level and measures absorbance. Once established, the linear relationship will be used to estimate the nitrate level in water from a measurement of absorbance. What is the equation of the line used for estimation? What is the estimated nitrate level in a water specimen with absorbance 40? c. Do you expect estimates of nitrate level from absorbance to be highly accurate? Why?

If a new element were discovered and it was found to form 1-ions, in which group would you place it in the periodic table? Enter the group number.

Where: [OH^-] = hydroxide ion concentration (a) Use the rules for logarithms and exponents to solve for pOH in terms of [OH^-]. pOH =

When buyers from Chipotle purchase organic meat and vegetables, they are part of the market.

Where is the suprachiasmatic nucleus (SCN) located? In neurons The pineal gland The hypothalamus The amygdala

Taking logarithms and antilogarithms is necessary to solve many chemistry problems. For practice, complete the following table, where N is a number. N ln N log N --------- 6.18 □ □ 3.405 -0.380

If a bacterial cell is placed in 100% alcohol, what happens to the water in the cell? Hydrolysis Water enters the cell Water leaves the cell

Water Oxygen

The combustion of 4.00 grams of milk in a bomb calorimeter resulted in a temperature increase of 3.4°C. qcomb = -840 J What is the heat capacity of the calorimeter? Ccal = [?] J / °C Enter the magnitude. Do not round until the end. Use significant figures.

Complete the table below by writing the symbols for the cation and anion that make up each ionic compound. The first row has been completed for you. ionic compound cation anion ------------------------------- NaCl Na+ Cl- AuBr3 MnI4 Cr2 S3 FeCl2

Stores that remain open 24 hours, seven days a week, are providing utility to their customers. Multiple Choice time schedule service possession

(d) Secondary alkyl halides can undergo SNI and SN2 reactions. If I wish to carry out an SN2 reaction should I use polar protic solvents such as ethanol or polar aprotic solvents such as acetone or tetrahydrofuran, THF?

A chemist prepares a solution of iron(III) bromide (FeBr3) by weighing out 180.8 of iron(III) bromide into a 300. miL volumetric flask and filling the flask to the mark with water. Calculate the concentration in g / dL of the chemist's iron(III) bromide solution. Be sure your answer has the correct number of significant digits.

Fill in the missing symbol in this nuclear chemical equation. 6^11 C rightarrow 5^11 B +

A piece of sodium metal is submerged in mineral oil for storage. The sodium displaces 10.7 cubic centimeters of mineral oil. If the density of sodium metal is 0.972 g / cm^3, what is the mass in grams of the submerged piece?

What is the volume, in milliliters, of 30.0 g of liquid if its density is 2.00 g / mL?

Write the chemical formula of each of the acids listed in the table below. acid chemical formula --- --- iodic acid sulfurous acid hydrosulfuric acid nitrous acid

H2O2 contains equal parts by weight of hydrogen and oxygen. (A) True (B) False

How does the amount of hydrochloric acid added before the indicator changes color relate to the neutralizing ability of the antacid? 1 (best antacid) Sodium bicarbonate 2 Calcium carbonate 3 Chewable calcium carbonate 4 Alumina/magnesium trisilicate 5 (worst antacid) Famotidine

If 2.00 grams of CO2 were produced when 4.00 grams of C5H12 were combusted in excess oxygen, what is the percent yield of the combustion reaction? A) 12.2 % B) 16.4 % C) 22.4 % D) 48.8 % E) 82.0 %

CH3-CH2-CH-CH2-CH1=CH-CH2-CH2-CH3

The mass of a cube of metal is 63.53 grams. The cube of metal is placed into 64.7 mL of water. Determine the new volume of water if the density of the metal is 9.15 g / cm^3. Record your answer to three decimal places. Do not put units in your answer!

Existe uma série de indicadores que auxiliam na identificação da situação pela qual uma empresa está passando. Cada conjunto de indicadores tem suas finalidades próprias. A respeito dos indicadores de giro, analise os itens a seguir e assinale a alternativa correta: 1. Prazo médio de estocagem 2. Prazo médio de pagamento a fornecedores 3. Ciclo financeiro 4. ROA Apenas os itens 1, 2 e 4 representam indicadores de Giro Apenas os itens 1, 2 e 3 representam indicadores de Giro Apenas os itens 1, 3 e 4 representam indicadores de Giro Apenas os itens 2, 3 e 4 representam indicadores de Giro Todos os itens representam indicadores de Giro

Select all the following elements that you would classify as a metal (Select all that apply): Lithium Nitrogen Oxygen Iron

Classify each chemical reaction: Reaction Type 2 NaClO3(s) → 2 NaCl(s) + 3 O2(g) choose one Fe(s) + CuSO4(aq) → FeSO4(aq) + Cu(s) choose one 2 Li(s) + 2 HCl(aq) → 2 LiCl(aq) + H2(g) choose one

What is the name of the oxyacid H2SO3? Select the correct answer below: siliconic acid sulfurous acid hyposulfuric acid hydrogen sulfide

Multiple Select Question Select all that apply lodine compounds are commonly used for which of the following? Treatment of skin wounds Household cleaning Disinfection of food preparation equipment Antisepsis of skin Disinfection of medical equipment

The molecules in a solid lump of sugar do not move.

Question 4 ( 0.5 points) The thin, light-sensitive membrane that lies at the back of the eye and contains the photoreceptor cells is the: 1) fovea. 2) optic disk. 3) retina. 4) optic nerve.

Question 2 (4 points) The athletic trainer is most directly responsible for what phases of health care in an athletic environment: Prevention of athletic injuries Diagnosis of athletic injuries First aid and injury management Implementation of prescribed rehabilitation All of the above

The suffix that means "to surgically creating an opening" is . A. -ostomy B. -plasty C. -otomy D. -ectomy

You place ice cubes in water and you notice after a few hours, the ice cubes melted into the water. This is.... a physical property a chemical property a physical change a chemical change

7) Find the mass of 250.0 mL of benzene. The density of benzene is 0.8765 g / mL. 8) A block of lead has dimensions of 4.50 cm by 5.20 cm by 6.00 cm. The block has a mass of 1587 g. From this information, calculate the density of lead.

Fill in the missing information. Make sure you have a periodic table handy.

The amount of CO2 emissions, E (in billions of tons), produced by the United States t years after 2000 is given by the function E(t). In 2010, the United States produced 5.5 billions of tons of CO2 emissions. Express this information in terms of the function E(t).

4. The wilcoxon rank sum test is a nonparametric test used to determine whether two independent samples were selected from population having the same distribution. True False

Multiple Choice Question What type of isomers are the two structures shown in this image? Cis-trans isomers Structural isomers Stereoisomers Enantiomers

An old 0.500 L lecture bottle of triethylamine (N(CH2CH3)3) was found in a lab and needed for a synthesis reaction. A pressure regulator indicated a pressure of 33.0 psi, and the lab was at room temperature (25°C). What mass of vaporized triethylamine was left in the lecture bottle?

What is the primary purpose of the Safety Data Sheet (SDS)? Multiple Choice Single-Answer (Please select an appropriate answer from the below list) A Advertise the risk and benefits of the product. B Advertise where the product can be obtained. C Inform the user of the use of the product. D Inform users about product properties and safety.

Select from the dropdown menu above the table to review the number of moles of each element in the flask containing one mole each of CH4, NH3, H2 S, and CO2 added to 55.5 moles of water. What is the maximum number of moles of glycine (C2 H5 NO2) that could be made in the flask if no other molecules were made? 1 mole of glycine 2 moles of glycine 5 moles of glycine 120 moles of glycine Submit Request Answer

State whether the following rule defines y as a function of x or not. x 80 15 0 -1 0 15 80 y 9 4 1 0 -1 -4 -9 Is y a function of x? A. No, because at least one y-value of the given rule corresponds to more than one x-value. B. No, because at least one x-value of the given rule corresponds to more than one y-value. C. Yes, because each x-value of the given rule corresponds to exactly one y-value. D. Yes, because each y-value of the given rule corresponds to exactly one x-value.

1.5 points How can I measure 25.2 g of a solid chemical (without using electricity)? Triple Beam Balance Thermometer Scoopula Pipet

What is the atomic number of the isotope with the symbol ^17 mathrmCl^17 ?

What determines the atomic number of an atom? A. The number of protons B. The mass C. The charge D. The number of neutrons

Write the chemical symbols for three different atoms or atomic cations with 10 electrons.

Chemistry

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