Chemistry Homework Questions & Answers Archive

Multiple Cholce Question Unemployment that occurs when the skills that some workers have to offer simply do not match the skills needed by firms in the economy is: cyclical unemployment. frictional unemployment. structural unemployment. industrial unemployment.

Si tienes 500 ml de una disolución 0.125 N de acido sulfúrico y la quieres diluir para tener una disolución 0.0300 M. ¿Cuánta agua tienes que agregar? (1 punto) Considera el siguiente proceso: H₂SO₄ → 2H⁺ + SO₄²⁻ Masas molares g / mol Na Cl Ba Ca K Cr Bi S O H P C 23 35.5 137.3 40 39.1 52 209 32 16 1 31 12

What conditions will cause a redox reaction to be nonspontaneous? A. The reduced element is higher on the potential list than the oxidized element. B. The sum of the voltages of the oxidation and reduction halfreactions is positive. C. The half-reaction for the reduced element has a negative standard potential. D. The sum of the voltages of the oxidation and reduction halfreactions is negative.

What type of bonding describes the following: Two atoms that are bonded in such a way that one member of the pair is supplying both electrons that are shared. ionic coordinate covalent metallic polar covalent

Determine if each compound has a chirality center. Select the single best answer for each part. Part 1 of 3 CH3CHClCH2CH3 yes no Part 2 of 3 yes no

Question In the description of the following experiment, determine the experimental factor. A pharmaceutical company conducted an experiment to test a breakfast drink for school children. The company enrolled students for the experiment in the age group of 6 to 10 and divided them into two groups. One group received the new breakfast drink with their normal breakfast, and the other group drank the same amount of a similar-looking juice. Identify the experimental factor. Select the correct answer below: the amount of drink given to each group the students in the two groups the students who received the new breakfast drink the type of drink given to each group FEEDBACK MORE INSTRUCTION SUBMIT

Weak acids differ in their relative strength; the same is true of weak bases. If base X is stronger than base Y, then the conjugate acid will be than the conjugate acid HY.

One way to enhance your learning in chemistry is to study a little every day, retest every few days, go to office hours, study different ideas at the same time, all the above

Solid barium carbonate (BaCO3) decomposes into carbon dioxide gas and solid barium oxide. Write a balanced chemical equation for this reaction. BaCO3 → BaO + CO2

In which cycle does the atmosphere play virtually no role? a.) nitrogen b.) oxygen c.) hydrological d) phosphorus

Question 15 The most important monosaccharide is fructose. lactose. glucose. maltose.

Dynamic equilibrium is . continuous change nonchanging internal conditions balanced change

Multiple Choice Question Evolutionary trends between species are often studied in which discipline? Constructive anatomy Complex anatomy Comparative anatomy Compatible anatomy

Naming Polyatomic Ionic Compounds Practice naming ionic compounds containing polyatomic ions. Li3PO4 CaSO4 Al(OH)3 Phosphate Sulfur Phosphide Oxygen hydride Hydride Calcium Oxygen Sulfate Aluminum Sulfide Lithium Hydroxide

Multiple Choice Question The name of the thyroid hormone with four iodine atoms is isthmus thyroxine triiodothyronine pars

Which result occurs during an exothermic reaction? (1 point) Light is released into the environment, while heat is absorbed. Light and heat are absorbed from the environment. Light or heat are released into the environment. Heat is released into the environment, while light is absorbed.

A nickel is found to have a volume of 2.81 * 10^4 liters. Show, using unit analysis, what the volume of the nickel is in quarts.

What element would have a mass number of 7 and 3 protons? N Ne Li Be

A 3 mg / min dosage is ordered. The solution strength is 2 g in 500 mL.

In neutral atoms, the number of protons and electrons is equal. Since protons are assigned a +1 charge and electrons are assigned a -1 charge, the atom with equal amounts of protons and electrons is neutral. In ions, this is not so. In ions, the number of protons and electrons are either gained or lost electrons. So, if lithium, Li, is written as Li+, you know that lithium has lost one electron. In losing one electron, lithium will have one proton more than its number of electrons, producing an offset of +1 in charge. Ions can have a variety of charges, such as +, -, +2, -2 and so on. (For +1 and -1 charges the "1" is sometimes not written and only the + and - are written.) Remember: When ions are formed only electrons are added or removed. The number of protons cannot be changed. Doing so would change the identity of the element (as is done in a nuclear reaction). It is always electrons being added or removed from an atom to form an ion. Fill in the blanks to determine the number of protons and electrons in an oxygen ion. (Consult the periodic table to determine the number of protons in a neutral oxygen atom.) The O^2- ion has protons and electrons. Express your answers as integers separated by a comma. If a neutral atom gains or loses electrons, it will become a charged particle called an ion. Cations have a positive charge, and anions have a negative charge. For example, the figure below depicts a sodium atom becoming a 1+ cation by losing one electron, and a chlorine atom becoming a 1- anion by gaining an electron. After which, the sodium cation has a total of 10 electrons and the chloride anion has a total of 18 electrons.

Question 18 Ionic bonds are chemical bonds formed by the: sharing of electrons between molecules. donation of protons from one atom to another. transfer of electrons from one atom to another. acceptance of neutrons from one atom by another.

What is the term for the difference between the amount of good consequences and the amount of bad consequences resulting from a choice? Duty Happiness Consequences Descriptive ethics Submit answer

Count the significant digits in each of these measurements: measurement number of significant digits ------ 3.2 × 10^-2 mL □ -6.0 × 10^-3 kJ / mol □ 43600 kg □

ZnO(s) + 2HCl(aq) → ZnCl₂(aq) + H₂O(l) ΔH° = +14.4 kJ/mol + Spontaneous at low temp. Co(s) + Cl₂(g) → CoCl₂(s) ΔH° = +10.4 kJ/mol + Spontaneous at low temp. NiAl(s) → Ni(s) + Al(s) ΔH° = +85.1 kJ/mol + Spontaneous at high temp. NaN + O₂(g) → Na₂O(s) ΔH° = -180.7 kJ/mol - Spontaneous at all temps. 3O(s) → O₃(g) exothermic - Spontaneous at low temps.

Select are macronutrients made of sugars and starches and yield 4 calories per gram. Select are macronutrients made of amino acids and yield 4 calories per gram. Select are macronutrients that provide twice as much energy, yielding 9 calories per gram.

Note: Typically, chemists write the C first, followed by the H answer

Which of the following is equal to 1.00 mole of substance? 6.02 × 10^23 sodium atoms, Na 6.02 × 10^23 iodine molecules, I2 6.02 × 10^23 sodium iodide formula units, NaI all of the above none of the above

What type of chemical reaction is illustrated in the following example? Zn(s) + HCl(aq) -> ZnCl2(aq) + H2(g) A) combination reaction B) decomposition reaction C) single-replacement reaction D) double-replacement reaction What is the predicted product from the following combination reaction? Sr(s) + Br2(l) A) SrBr B) Sr2Br C) SrBr2 D) Sr2Br3

Classify the chemical equations as being balanced or not balanced. 2 CO+2 NO-2 CO2+N2 6 CO2+6 H2O-C6H12O6+O2 H2CO3-H2O+CO2 2 Cu+O2-CuO

3.4 ALEKS Homework: Rational Exponents Question 23 of 24 (1 point) I Question Attempt: 1 of U Evaluate the following. Click on "Not a real number" if applicable. (a) -36^(1/2)= (b) (-243)^(1/5)=

Question 26 The following compound is: (R)-3-chloropent-1-ene Cl-C-CH2-CH3 H H-C=C H H O True O False

Which are the very small particles that make up matter?

Read the Personality Assessment section and answer the following questions. Port 1 of 3 An item on a personality assessment is high in face validity if Multiple Choice it provides similar responses over time. it seems like it fits the trait it is supposed to measure. it is able to successfully differentiate between people who have the trait and those who do not. it can be demonstrated to be related to other reliable measures of personality.

14. In Translation, this nucleotide sequence specifies the amino acid sequence.

Identify the functional group on the following structure: carbonyl phosphate carboxyl amino sulfhydryl

Aspartame (Nutrasweet): C14 H18 N2 O5.

Identify the behavior of the following molecule based on its functional group: It acts as a weak acid and makes molecules more soluble in water. It acts as a base. It acts as a strong acid. It is used to build larger organic molecules. It aids in protein structure.

What is the molarity of a solution with 15.1 g of glucose (molar mass: 180.16 g / mol) dissolved in water to a total volume of 450.0 mL? 0.186

880.62 g ÷ 0.67 mL = □ g/mL 0.934 cm × 4.625 cm = □ cm² 371.2 g ÷ 68.383 mL = □ g/mL

Question 5 How many hydrogens are connected to the circled carbon? 0 1 2

Identify the level of protein structure for the following: - the shape of a globular protein - a protein with two or more peptide chains - order of amino acids in a protein - beta-pleated sheet - disulfide bonds between R groups

Balance the chemical equation below using the smallest possible whole number stoichiometric coefficients. N2(g)+H2(g) rightarrow NH3(g)

What is the chemical formula for Fe2O3?

Keisha's teacher gives her the following information: - m, n, p, and q are all integers and p ≠ 0 and q ≠ 0 - A = m/q and B = n/p What conclusion can Keisha make? A · B = mp + nq/PV, so the product of two irrational numbers is an irrational number. A + B = mp + np/p, so the sum of two rational numbers is a rational number. A · B = mp + nq/N, so the product of two rational numbers is a rational number. A + B = mp + nq/pP, so the sum of a rational number and an irrational number is an irrational number.

Which of these statements is true about isomers? (check all that apply) They have the same chemical formula but different structure They can perform the same functions and are biologically interchangeable Even a small change in structure can affect the function

According to the following reaction, what volume of 0.305 M AgNO3 is required to react with 155.0 mL of 0.274 M Na2SO4 solution? 2 AgNO3(aq) + Na2SO4(aq) → Ag2SO 4(s) + 2 NaNO3(aq) 139 mL 345 mL 278 mL 173 mL 581 mL

Module OI Homework Question 18 of 18 (1 point) Question Attempt 1 of Unlimited Experiments were done on a certain pure substance X to determine some of its properties. There's a description of each experiment in the table below. In each case, decide whether the property measured was a chemical or physical property of X, if you can. If you don't have enough information to decide, choose can't decide in the third column. property experiment physical or chemical? P A small sample of X is dissolved in water. Drops of another solution, containing dissolved sodium hydroxide, are slowly added, and a pH indicator is used to determine when the sodium hydroxide has completely reacted with X. From the amount of sodium hydroxide needed, the value of P may be calculated. physical chemical (can't decide) D A sample of X is carefully weighed and put inside a vented flask. Water is added to the flask until it just covers the sample, and the volume of sample and water is recorded. Then the sample is removed and the volume of water alone recorded. From the mass of the sample and the difference in volumes, the value of D may be calculated. physical chemical (can't decide) C A sample of X is carefully weighed and put inside a sealed calorimeter. Pure oxygen gas is injected into the calorimeter, and the mixture ignited. After all of X has reacted with the oxygen gas, the temperature rise of the calorimeter is measured. From this change in temperature the value of C may be calculated. physical chemical (can't decide)

Which of the following structures is MOST stable? cyclobutane cyclopropane cyclohexane cycloheptane

Hydrochloric acid is typically purchased in a relatively highly concentrated form and then diluted by adding slowly to water to save money. The concentration of the purchased solution is 37.0% by mass HCl, and this solution has a density of 1.20 g/mL. What volume of the concentrated HCl solution is the correct amount needed to make 3.7 L of 0.435 M HCl? - 130 mL - 8.5 mL - 12 mL - 1.1 L - 96 mL

Which two characteristics of the matter change?

What stretching frequencies (in cm^-1) are present in the structure below?

Fill in the Blank Question By providing a means by which microorganisms could be viewed, the development of the established the science of microbiology.

What is the concentration of H+ ions in coffee given that it is slightly acidic? 10^-2 10^-5 10^-7 10^-8

Which describes a climate effect on the rate of weathering? Cold climates favor mechanical weathering. Chemical reactions occur slower at higher temperatures. Lower precipitation levels lead to more chemical reactions. The chemical reaction rates of minerals are not impacted by temperature.

Decide whether each row is a set of resonance structures for a single molecule and select "yes" or "no" in the last column.

12 / 20 Organic compounds are composed of Carbon Carbon, Hydrogen, and Oxygen Carbon and Hydrogen Carbon and Vitamins

Composed principally of amino acids, and acting as biological catalysts, facilitate metabolic activities of the cell. cofactors ribosomes enzymes ribozymes

Listen The Lewis structure of phosphoric acid contains 1 double bond, 6 single bonds, and 8 lone pairs. True False

Choose the best Lewis structure for OCl2. Cl-O=Cl: Therefore Cl=O=Cl: : Cl-O-Cl: : CCl=O-Cl :

A fictitious element, Fi, consists of three isotopes: Fi-16, Fi-17, and Fi-19. The notation Fi-16, Fi-17, and Fi-19 indicates that all three are atoms of Fi, each with the same number of protons, yet they have different masses because they have different numbers of neutrons. The masses of these isotopes, in units of atomic mass units (amu), and their percent abundances are listed below. Fi-16: 11.22%, 16.11 amu Fi-17: 18.43%, 17.04 amu Fi-19: 70.35%, 19.13 amu Based on this information, calculate the average atomic mass of Fi.

What is FALSE about the three orbitals in the 2 p sublevel? The orbitals have the same dumbbell-like shape. The orbitals have similar, but different energies. The orbitals are the same distance away from the nucleus. The orbitals are each oriented in a different direction. Each orbital can hold two electrons with opposite spins.

Draw the resulting resonance structure.

H2CO3 + Ba(OH)2 → BaCO3 + H2O

The Gram-negative cell wall is characterized by a(n) that contains a molecule called outer membrane; lipopolysaccharide outer membrane; mycolic acid inner membrane; lipopolysaccharide inner membrane; mycolic acid

Part A Consider this balanced chemical equation: H2O2(aq) + 3 I^-(aq) + 2 H+(aq) → I3^-(aq) + 2 H2O(l) In the first 10.0 seconds of the reaction, the concentration of I^- drops from 1.170 M to 0.810 M. Calculate the average rate of this reaction in this time interval. Express your answer with the appropriate units. The value should be entered as a single number or in scientific notation.

How many molecules are in 0.8 moles of NO2 ? [?] × 10^[?] molecules of NO2 Remember: 1 mole = 6.02 × 10^23 molecules

True or false: Molecules that contain covalent bonds are rigid, inflexible structures.

Structures that extend from the kinetochore of each chromatid to the centrioles during mitosis are called - centromeres - pertcentriotar material - spindle fibers.

What is the molarity of an aqueous solution that contains 0.0720 g C2H3O2 per gram of solution? The density of the solution is 1.04 g / mL

The supervisor will give the orders when she's ready to start.

93 mol/L × 21 L = square mol 560.7 mol ÷ 51.0 L = square mol/L 20.94 g/mL × 80 mL

Which bond form substances with low melting and boiling points? - Covalent - Ionic

Coating Buffer (1X PBS) Coating Buffer is ready to use from the manufacturer (1X Dulbecco's Phosphate Buffered Saline, Sigma Product No D 537-500 mL ) Alternatively, 1X PBS maybe prepared by diluting 100 mL of 10 X PBS with 900 mL of water Store at room temperature for up to two weeks.

docs.google.com Last Name * nay What is a renewable resource? * a. A resource that takes millions of years to form b. A resource that can be replaced naturally in a short time c. A resource that cannot be used again d. A resource that is very expensive Which of these is a nonrenewable resource? * a. Wind energy b. Solar power c. Coal d. Trees

Which of the following is true regarding the transport of carbon dioxide? Most CO2 is transported dissolved in the blood plasma. Most CO2 is transported attached to hemoglobin. Most CO2 is transported in plasma as bicarbonate ions. Most CO2 is transported as chloride ions. Most CO2 is transported attached to the heme portion of hemoglobin.

Question 2 (1 point) (18.5) Which of the following is the reaction for the acid hydrolysis of N methylacetamide? CH3-C-NH-C-CH3+H2O -> CH3-C-NH2+CH3OH

In the Lewis Dot structure of diatomic elemental chlorine gas, how many bonds are between the two atoms?

The dosage form normally repackaged in a pharmacy is the: A. Tablet form B. Capsule form C. Liquid form D. All the above The manufacturer expiration date of a drug is 4 / 22, the drug expires on: A. April 1, 2022 B. April 15,2022 C. April 30, 2022 D. April 31, 2022 Compounding pharmacies must follow each state's board of pharmacy regulations, in addition to standards A. USP <711> B. USP < 795> C. USP < 797> D. USP <800> The punch method is used to prepare: A. Solutions B. Tablets C. Capsules D. Ointments

2 sodium atoms, 1 sulfur atom, and 4 oxygen atoms.

Question 25 In the calcium atom represented by the symbol Ca, there are 20 protons, 20 neutrons, and 20 electrons. True False

13. Identify which: a. The most reactive element in group 2 b. The most reactive element in group 16 c. The smallest element in period 4 d. The second-most reactive element in group 15 e. The most electronegative element f. The most metallic element

Which of the following demonstrates a chemical reaction of water? - Water dissolves sugar. - Water produces gas with sodium metal. - Water boils to produce steam at 100 degrees Celsius (212 degrees Fahrenheit). - Water and oil separate when combined.

Calculate the pH of a 0.70 M solution of HOI. The Ka for HOI is 3.2 x 10^-11, (A) 5.75 (B) 5.51 (C) 5.40 (D) 5.32 (E) 5.27

Complete the last two columns of the table. The molar masses of the substances are given in parentheses. Use the space below to show your work Quantity Number of moles Number of Particles a. Atoms is 14.0 g of neon, Ne(20.18 g / mol)

f for the elements below. Round all atomic masses to the nearest whole number: Element Symbol Atomic Number Atomic Mass # of Protons # of Electrons # of Neutrons sodium Cu silver calcium Pb radon

Use this isotope to answer the following questions. Kr How many electrons does krypton-73 have? 36 p+, [?] e-, square n^0

In an ideal gas, gas particles do not attract one another. True False

In the titration of 38.0 mL of 0.55 M HF(Ka=7.2 x 10^-4) with 0.55 M NaOH, what is the pH after 22.0 mL of NaOH has been added? (A) 3.28 (B) 3.14 (C) 1.99 (D) 9.67 (E) 12.96

This question has two parts. First, answer Part A. Then, answer Part B. Part A a. Determine the value of k from the given graph. f(x)=3^x ; g(x)=f(x)+k The value of k is □

Which diagram represents an element that is likely to form covalent bonds?

What is a technique used in procurement planning? - Special development projects - Make-or-buy analysis - Project Management Office (PMO) - Unit price contracts

What is the name for the H3O+ ion? What is the name of the OH- ion?

Which element is in the same group as Chlorine? Al - Aluminum Br - Bromine Kr - Krypton Ne - Neon

A pair of shared valence electrons is referred to as a(n): hydrogen bond. van der Waals interaction. hydrophobic effect. covalent bond. ionic bond.

Based on the chemical structures in the image, which type of hormone is depicted in C? Amine hormone Peptide hormone Steroid hormone Protein hormone SAVE CONTINUE

Pentane has three structural isomers. True False

Which of the following would you expect to be hydrophilic? Choose all that apply. Hydrocarbons CH 3 OH C3H8 Cl -ions Nonpolar molecules Polar molecules

Which has the correct name-formula combination? A Chlorine pentafluoride - CIF B Diphosphorus pentoxide - P2O C Carbon tetraiodide - Cl4 D Sulfur tetrafluoride - SF

How many electrons are transferred in the reaction represented by the following equation? (9.1) CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(g) (a) 0 (b) 2 (c) 4 (d) 8

Question 35 (1 point) The phase of hemostasis that is most similar to milk curdling (clotting up) is: vasoconstriction. hemophilia. platelet plug formation. coagulation.

Which element is reduced in the reaction represented by the equation: 2 Mg + O2 -> 2 MgO if Mg goes from 0 to +2 and O goes from 0 to -2?

The half-life of Radium-226 is 1590 years. If a sample contains 300 mg, how many mg will remain after 3000 years? mg Give your answer accurate to at least 2 decimal places.

A sample of gas in a flexible container initially occupies a volume of 3.65 L at 271 K. Then, the volume of the gas inside the container decreases to 2.99 L at 290 K and 1.76 atm. The number of moles of the gas remains constant.

What are substrates?

Multiple Choice Question The myelin sheath is a spiral layer of insulation around a nerve fiber. dendrites muscle tissue insulation scar tissue

Erosion and Soil Issues Over-application of fertilizers can lead to which of these negative issues in water? increased clarity a decrease in sediments eutrophication increased dissolved oxygen

Evaluate the following reaction. What is the precipitate that forms? 3 Na2 S(aq) + 2 FeCl3(aq) ⟶ Precipitate:

2. Calcium oxide reacts with water to produce calcium hydroxide and 65.2 kJ of heat in the following reaction. CaO(s) + H2O(l) -> Ca(OH)2(s) ΔH = -65.2 kJ / mol a. How much heat is released when 78.0 g of calcium oxide reacts with excess water?

Which type of enzyme inhibitor decreases affinity for binding the substrate? Answers A - D A uncompetitive B none of the above C noncompetitive D competitive

What kind of bond is formed in the reaction shown below? A) metallic bond B) hydrogen bond C) network bond D) coordinate covalent bond

Question Which of the following is a state function? Select the correct answer below: heat internal energy work all of the above

A certain chemical reaction releases 16.7 kJ / g of heat for each gram of reactant consumed. How can you calculate the heat produced by the consumption of 1.1 kg of reactant? Set the math up. But don't do any of it. Just leave your answer as a math expression. Also, be sure your answer includes all the correct unit symbols. heat =

For which of these calibration values can you estimate to one more place value? 40 mL 75 mL 20 mL 100 mL

Which drawing is a structural model of C3H8?

Was sind Cottrell-Wolken und wozu führen sie?

A moderate fever for an otherwise healthy adult is 99 °F. Convert this temperature to degrees Celsius. Be sure your answer has the correct number of significant digits.

BALANCING EQUATION Reactants Products

In the reaction 2 H2O → 2 H2 + O2, 2.0 mol water will produce how many grams of O2?

Non-Standard Cells Cu^2+(aq) + Zn(s) ⇌ Cu(s) + Zn^2+(aq) What happens to the cell potential with the change in conditions? The cell potential will be greater than 1.10 V. A new cell is constructed in which the copper concentration is raised to [Cu^2+]-2.0 M, the zinc concentration is held standard at [Zn^2+]-1.0 M, and the temperature is held the same. The cell potential will remain 1.10 V.

How could we identify whether a covalent compound is polar or nonpolar? by analyzing its solubility by determining its density by determining its conductivity by observing its color

Use the solubility table to predict if a precipitate will form in the double replacement reaction.

Multiply or divide the following measurements. Be sure each answer you enter contains the correct number of significant digits. 788.5 g / 0.58 mL = □ g/mL 495.12 mol / 70.5 L = □ mol/L 78.1 mol/L × 18 L = □ mol

A short-term job or work project that can be paid or unpaid and can lead to a full-time, paying position is called a(n) a. job shadow b. temp job c. internship d. cooperative program

In a solution, the concentration of KOH is 1.2 × 10^-3 M. Calculate the: a. [H^+]

Why are the sodium and chlorine ions stable? sodium lost one electron and chlorine gained one electron. sodium gained one electron and chlorinelost one electron they exchanged protons sodium lost a neutron and chlorine gained a neutron

Provide an IUPAC name for the structure shown. (Use cis/trans terms for cyclic structures. Do not specify stereochemistry in other cases. It is not necessary to use italics in writing compound names.)

Write an acceptable IUPAC name for the compound below. (Only systematic names, not common names are accepted by this question.) Keep the information page open for feedback reference. The IUPAC name is

Multiple Choice Periodic health claim payments MUST be made at least A. weekly B. annually C. daily monthly

An adsorbent plate containing specific nucleic acid sequences from multiple types of pathogens, and that is used for hybridization reactions in infectious disease diagnosis, is called a(n)

In a(n) square bond, one or more valence electrons are lost from one atom and transferred to a second atom; therefore no electrons are actually shared.

When a slightly positive hydrogen atom forms a weak bond to an electronegative atom nearby, this weak attraction is called a(n) bond. nonpolar covalent hydrogen ionic

Which reaction is the opposite of photosynthesis? aerobic respiration anaerobic respiration Calvin cycle dark reaction

1. Calcium (Ca) 2. Boron (B) 3. Neon (N) 4. Chlorine (Cl) 5. Tungsten (W) 6. Lead (Pt) 7. Silicon (Si) 8. Antimony (Sb) 9. Mercury 10. Located to the right of the Periodic Table 11. Located to the left of the Periodic Table 12. Located along the zigzag (stairs) line of the Periodic Table 13. Majority of the elements 14. Solid, may have luster, and is brittle 15. Solids are malleable 16. Poor electrical and thermal conductors 17. Have elements in the solid, liquid, and gas phase at standard temperature and pressure (STP) 18. Elements only exist as solids at standard temperature and pressure (STP) 19. Are good electrical and heat conductors, therefore ductile 20. Solids are generally brittle 21. Usually a gas at room temperature 22. Reactivity depends on other elements involved in reactions 23. Non-lustrous appearance, dull

What is the molarity of an HCl solution if 43.6 mL of a 0.125 M NaOH solution are needed to titrate a 25.0 mL sample of the acid according to the equation below (show your calculations)? NaOH(aq) + HCl(aq) → H2O(l) + NaCl(aq)

A chemist needs to know the mass of a sample of MgCl2 to 2 significant digits. He puts the sample on a digital scale. This is what the scale shows: 0 2 0 8 3 7 g If this measurement is precise enough for the chemist, round it to 2 significant digits. Otherwise, press the "No solution" button. g 10 No solution

Multiple Choice 1.9 points Which of the following has chemical properties most similar to zinc? A) Al B) Ga C) Cd D) Ag Multiple Choice 1.9 points Given the chemical formulas MgO, Al2O3, and SiO2, predict the formula for germanium oxide, Ge ? O ? . A) GeO B) Ge2O C) GeO2 D) Ge 2 O 3

Part 2: Moles ↔ Particles Conversions 5. 0.0455 moles of HCl to number of molecules

0.390 mol of octane is allowed to react with 0.700 mol of oxygen. Which is the limiting reactant?

LiC2H3O2 MgCr2O7 FeSO4 PbCO3 BaCO3 FeCrO4 Cr(ClO3)2 CaSO3 Hg(OH)2 Sn(SO4)2

What is the oxidation number of Mn in MnO4-?

Multiple Select Question Select all that apply Which of the following are the expected IR absorptions for an alkene, which would help to distinguish its IR spectrum from that of an alkane or al that apply. strong peak at 3000 - 2850 cm^-1 medium peak at 3150-3000 cm^-1 strong peak at 1800 cm^-1 medium peak at 1050 cm^-1

How does fluorine become an anion? Fluorine is a group 7 element! It loses 1 electron. It gains 1 electron. It gains 3 electrons. It loses 2 electrons.

Quiz: Biconditionals and Definitions CR Geometry A (GP) 24-25 / 2:Reasoning and Proof 1. Is the following statement a good definition? Why? A penny is a United States coin worth one cent. No, it is not. The statement is not precise. No, it is not. The statement is not reversible. Yes, it is. The statement is precise and reversible. Yes, it is. The statement is precise.

What is the percent composition of oxygen in carbon dioxide (CO2)?

Keq Calculations: Tiny K Values [NOCl]/K=93,750 Can you neglect the change in "X" based on the " 500 Rule"? No, the change in X cannot be neglected. There is not enough information to decide. Yes, the change in X can be neglected.

The reaction proceeds toward the products. Complete the ICE table below to find " X ". R 2 NO(g) ⇌ N2(g) + O2(g) 12.0 C E What is the value of " X " from the "ICE" table?

Write the formula for an example of each of the following compounds: a. nonpolar covalent compound b. polar covalent compound c. ionic compound

3. Using CD as the transversal, which angles are considered alternate exterior angles? - angle CAQ and angle DBO - angle CAB and angle UBO - angle QAB and angle ABO - angle AQU and angle BOR 4. Why are the alternate interior angles, the alternate exterior angles, and the corresponding angles equal in this model? - Since the shape is a parallelogram the transversal must cross two parallel lines. - Since the shape is a parallelogram the transversal must cross two perpendicular lines. - The angles are not equal they are all supplementary. 5. Critical Thinking Problem: Which of the following segments is NOT considered a transversal? - CD - Qu - RO - CA

which of the following observations would be the expected indication that a reaction has taken place when a solution of cesium sulfate is mixed with strontium nitrate?

2 H2(g)+S2(g) rightleftharpoons 2 H2 S(g) quad K=1.08 times 10^7 The current concentrations for the system are given below. What is the reaction quotient, Q, for the system? [H2] =0.500 M [S2] =0.500 M [H2 S] =9.00 M Q =[?]

Classify each chemical compound: compound type of compound PbCrO4 ◯ ionic ◯ molecular H2S ionic ◯ molecular Cl2O3 ionic ◯ molecular

Decide if each statement is true or false for the transformation pictured at the particulate level in the following illustration: Xe = brown F = green There are 2 atoms of Xe in both the reactants and the products. The number of F atoms in the reactants is greater than the number in the products. The illustration represents a valid chemical transformation.

What is the percent composition of sodium and chlorine in NaCl? (Round the percent to two decimal places)

What is the major organic product of the following reaction? → HgSO4, H2O, H2SO4 I II III IV Multiple Choice I II III IV

Select the correct answer. Which option describes a similarity and a difference between isotopes of an element? A. same atomic number; different number of protons B. same number of protons; different atomic number C. same atomic number; different mass number D. same mass number; different atomic number E. same number of neutrons; same number of protons

What is the major product of the following reaction?

Question Of the following halide compounds, which is the least soluble in water? Select the correct answer below: calcium chloride lithium chloride magnesium fluoride lithium fluoride

Which of the following structures have the correct common name? Aryl chloride I → Br Allyl bromide II Benzylic chloride Vinyl fluoride IV II and III III and IV II and IV I and II

What is the mass of 3.25 moles of water? Show your calculations.

Up-regulation involves the loss of receptors and prevents the target cells from overreacting to persistently high hormone levels.

In an experiment, propan-1-ol is made to react with butanoic acid, in the presence of concentrated sulfuric acid as a catalyst. The product is: a. propyl propanoate b. ethyl propanoate c. propyl butanoate d. butyl propanoate

Volume in graduated cylinder Water volume (mL) Volume of a drop 30.0 Water volume (mL) 1.00 Number of drops 18 Average drop volume (mL) 0.0556

Do the following statements describe a chemical or physical change? The helium gas inside a balloon tends to leak out after a few hours. chemical physical neither

Intermolecular forces are weaker than intramolecular forces (bonds).

Which molecules have the strongest intermolecular forces? BF3 H2S NH3 H2

Why does olive oil have a lower melting point than butter fat? Match the words in the left column to the appropriate blanks in the sentences on the right. hydrogen bonding interactions monounsaturated dispersion forces Olive oil has a lower melting point because it contains mostly monounsaturated fatty acids, whereas butter contains a large number of saturated fatty acids. A monounsaturated fatty acid has a kink in its carbon chain, which means it cannot pack together as tightly as the saturated hydrocarbon chains in butter and, therefore, does not experience as many dispersion forces as butter. saturated dipole-dipole interactions

Which ionic compound is used as a building material? salt limestone magnesium oxide iron oxide

Which of the following saturated solutions has the greatest [CO3]2- ? MgCO3 BaCO3 CaCO3 SiCO3

Isotopes are atoms of the same element that differ in their Multiple Choice 31 electron number. neutron number. proton number. chemical properties. atomic number.

Simplify 2 ln (x+2)-ln (x+2)-ln (2)-3. ln ((x+2)/2)-3 ln ((x+2)/5) ln ((x+2)/6) ln (x+2)-ln (6) ln (x+2)-ln (5)

During which phase change is energy absorbed by the substance? Freezing Condensation Melting Both a and b

O aspartame, um adoçante artificial, pode ser utilizado para substituir o açúcar de cana. Bastam 42 miligramas do aspartame para produzir a mesma sensação de doçura que 6,8 gramas de açúcar de cana. Sendo assim, quantas vezes, aproximadamente, o número de moléculas de açúcar de cana deve ser maior do que o número de moléculas de aspartame para que se tenha o mesmo efeito sobre o paladar? Dados: massas molares aproximadas (g / mol) açúcar de cana: 340 adoçante artificial: 300 Escolha uma opção: a. 100 b. 140 c. 200 d. 50 e. 30

8) Identify the following organic compound functional group. (b) Amine (d) Ester (e) Aldehyde (a) Amide (c) Alcohol

What is the name of the compound with the formula NaF? Name: What is the name of the compound with the formula BaBr2? Name: What is the name of the compound with the formula MgO? Name:

Complete the following solubility constant expression for CaF₂. Ksp=

Acetic acid is a weak acid present in commercial vinegar that can be used to create a buffer solution. Phosphoric acid Acetic acid Hydrochloric acid Formic acid

Determine which of the following pairs of reactants will result in a spontaneous reaction at 25°C. Cr^3+(aq) + Sn(s) Ni(s) + Ba^2+(aq) Sn^4+(aq) + Zn(s) Zn(s) + Na^+(aq) None of the above pairs will react.

Question 3 * 20 points 3. Which symbol represents an atom in the ground state with the most stable valence electron configuration? A) Ne B) B C) O D) Li Question 4 * 20 points 4. Given the equation representing a reaction:

Determine if the following statements are true or false. If the statement is incorrect, specify how you would change the statement to make it correct. 1. The formation of a mixture involves chemical combination of substances. 2. An element can be broken down into simpler substances. 3. The smallest particles unique to a compound are not the atoms. 4. A mixture is always made up of a combination of elements 5. A simple physical process cannot separate the substances in a mixture. 6. Simple physical processes can separate the elements in a compound because they are combined only physically.

1. How many moles of tetraphosphorus decaoxide are present in 3.21 grams of this compound? moles 2. How many grams of tetraphosphorus decaoxide are present in 4.03 moles of this compound? grams

Chemistry

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