Questions: 90. Which of the following compounds contains the Mn ion? a. MnS b. MnBr2 c. Mn2O3 d. MnO 91. What is the net charge of the ionic compound calcium fluoride? a. 2- b. 1- c. 0 d. 1+ 92. Which of the following units is NOT an official SI unit? a. kilogram b. ampere c. mole d. liter

90. Which of the following compounds contains the Mn ion?
a. MnS
b. MnBr2
c. Mn2O3
d. MnO

91. What is the net charge of the ionic compound calcium fluoride?
a. 2-
b. 1-
c. 0
d. 1+

92. Which of the following units is NOT an official SI unit?
a. kilogram
b. ampere
c. mole
d. liter

Transcript text: $\qquad$ 90. Which of the following compounds contains the Mn ion? a. MnS b. $\mathrm{MnBr}_{2}$ c. $\mathrm{Mn}_{2} \mathrm{O}_{3}$ d. MnO $\qquad$ 91. What is the net charge of the ionic compound calcium fluoride? a. 2- b. 1- c. 0 d. $1+$ $\qquad$ 92. Which of the following units is NOT an official SI unit? a. kilogram b. ampere c. mole d. liter

Solution

Solution Steps

Step 1: Identify the Compound Containing Mn Ion

The question asks which of the given compounds contains the Mn ion. All the options provided (MnS, $\mathrm{MnBr}_{2}$, $\mathrm{Mn}_{2} \mathrm{O}_{3}$, MnO) contain the Mn ion, as they all have manganese (Mn) as part of their chemical formula.

Step 2: Determine the Net Charge of Calcium Fluoride

Calcium fluoride is composed of calcium ions ($\mathrm{Ca}^{2+}$) and fluoride ions ($\mathrm{F}^{-}$). The formula for calcium fluoride is $\mathrm{CaF}_{2}$, indicating that there are two fluoride ions for each calcium ion. The net charge of the compound is calculated as follows:

Charge from calcium: $+2$
Charge from two fluoride ions: $2 \times (-1) = -2$

The total net charge is $+2 + (-2) = 0$.

Step 3: Identify the Non-SI Unit

The question asks which of the given units is not an official SI unit. The options are kilogram, ampere, mole, and liter. Among these, the liter is not an official SI unit. The official SI unit for volume is the cubic meter ($\mathrm{m}^3$).