Question 1

Which of the following compounds is a polyatomic ion, and what is its correct chemical formula?

Accepted Answer

Ammonium, $$\mathrm{NH_4$^+}$$

Question 2

Which of the following is the correct name for $$\mathrm{$$FeCl_3$$}$$?

Accepted Answer

Iron(III) chloride

Question 3

A sample contains $$3.01 	imes 10$$^{23}$$ molecules of carbon dioxide. How many moles of carbon dioxide are present?

Accepted Answer

$$0.25$$ mol

Question 4

Which of the following best describes the process of balancing a chemical equation?

Accepted Answer

Adding coefficients in front of compounds to ensure the same number of each atom on both sides

Question 5

Which of the following compounds is insoluble in water according to the solubility rules?

Accepted Answer

Silver chloride, $$\mathrm{AgCl}$$

Question 6

What is the percent composition by mass of hydrogen in water ($$\mathrm{H_2O}$$)?

Accepted Answer

$$11.2\%$$

Question 7

Which of the following is a correct net ionic equation for the reaction between aqueous solutions of sodium sulfate and barium chloride?

Accepted Answer

$$\mathrm{Ba$$^{2+}$$ (aq) + SO_4$^{2-} (aq) \rightarrow $$BaSO_4$$ (s)}$$

Question 8

A compound contains $$40.0\%$$ carbon, $$6.7\%$$ hydrogen, and $$53.3\%$$ oxygen by mass. What is its empirical formula?

Accepted Answer

$$\mathrm{CH_2O}$$

Question 9

Which of the following is a double displacement (metathesis) reaction?

Accepted Answer

$$\mathrm{$$AgNO_3$$ + NaCl \rightarrow AgCl + $$NaNO_3$$}$$

Question 10

How many grams of $$\mathrm{NaCl}$$ are present in $$0.50$$ moles of $$\mathrm{NaCl}$$? ($$\mathrm{NaCl}$$ molar mass = $$58.44 g/$$mol)

Accepted Answer

$$29.22 g$$

Question 11

Which of the following statements about electrolytes is correct?

Accepted Answer

Strong acids and soluble ionic compounds are strong electrolytes

Question 12

What is the oxidation state of sulfur in $$\mathrm{SO_2$}$$?

Accepted Answer

$$+4$$

Question 13

Which of the following is the correct balanced equation for the combustion of methane ($$\mathrm{CH_4$}) in $$oxygen?

Accepted Answer

$$\mathrm{CH_4$ + 2O_2 \rightarrow CO_2$ + 2H_2O}$$

Question 14

A solution is prepared by dissolving $$5.85 g of$$ $$\mathrm{NaCl} in $$enough water to make $$0.500 L of $$solution. What is the molarity of the solution? ($$\mathrm{NaCl}$$ molar mass = $$58.44 g/$$mol)

Accepted Answer

$$0.2 M$$

Question 15

Which of the following best describes a limiting reactant in a chemical reaction?

Accepted Answer

The reactant that determines the amount of product formed

Question 16

If $$2.0$$ mol of $$\mathrm{H_2$}$$ react with $$1.0$$ mol of $$\mathrm{O_2$} to $$form water, what is the limiting reactant?

Accepted Answer

$$\mathrm{O_2$}$$

Question 17

Which of the following is the correct formula for calcium phosphate?

Accepted Answer

$$\mathrm{Ca_3$(PO_4$)_2}$$

Question 18

A reaction has a theoretical yield of $$10.0 g $$and an actual yield of $$8.0 g. $$What is the percent yield?

Accepted Answer

$$80\%$$

Question 19

Which of the following is a correct example of a synthesis reaction?

Accepted Answer

$$\mathrm{2Na + Cl_2$ \rightarrow 2NaCl}$$

Exam 2 Study Guide: Chemical Formulas, Composition, Reactions, and Stoichiometry (Chapters 5-8)

Study Guide - Practice Questions

Study Guide - Flashcards