Question 1

Which of the following is the correct formula for the compound formed between magnesium and phosphate ions?

Accepted Answer

$$\mathrm{Mg_3$(PO_4$)_2}$$

Question 2

What is the correct name for the compound $$\mathrm{Fe_2$(SO_4$)_3}$$?

Accepted Answer

Iron(III) sulfate

Question 3

A sample contains $$0.5$$ moles of $$\mathrm{NaCl}. $$How many formula units are present in the sample? ($$N_A = 6.022 	imes 10$$^{23}$$)

Accepted Answer

$$3.011 	imes 10$$^{23}$$

Question 4

Which of the following ions has a $$2+$$ charge?

Accepted Answer

$$\mathrm{Ca$$^{2+}$$}$$

Question 5

What is the empirical formula for a compound containing $$40.0\%$$ carbon, $$6.7\%$$ hydrogen, and $$53.3\%$$ oxygen by mass?

Accepted Answer

$$\mathrm{CH_2O}$$

Question 6

Which of the following compounds contains a polyatomic ion?

Accepted Answer

$$\mathrm{$$KNO_3$$}$$

Question 7

Calculate the molar mass of $$\mathrm{Ca(OH)_2}.$$

Accepted Answer

$$74.10\ \mathrm{g/mol}$$

Question 8

Which of the following is the correct formula for ammonium sulfate?

Accepted Answer

$$\mathrm{(NH_4$)_2SO_4}$$

Question 9

How many oxygen atoms are present in $$2.0$$ moles of $$\mathrm{H_2SO_4}$$?

Accepted Answer

$$4.82 	imes 10$$^{24}$$

Question 10

Which of the following is the correct name for $$\mathrm{Cu(NO_3$)_2}$$?

Accepted Answer

Copper(II) nitrate

Question 11

A $$10.0 g $$sample of $$\mathrm{Na_2CO_3}$$ contains how many moles? (Molar mass $$= 106\ \mathrm{g/mol})$$

Accepted Answer

$$0.094$$ moles

Question 12

Which of the following is the correct formula for aluminum nitrate?

Accepted Answer

$$\mathrm{Al(NO_3$)_3}$$

Question 13

What is the percent composition by mass of oxygen in $$\mathrm{H_2O}$$?

Accepted Answer

$$88.9\%$$

Question 14

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

Accepted Answer

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

Question 15

How many grams of $$\mathrm{CO_2$}$$ are produced from $$0.50$$ moles? (Molar mass $$= 44.0\ \mathrm{g/mol})$$

Accepted Answer

$$22.0 g$$

Question 16

Which of the following is the correct name for $$\mathrm{K_2SO_4}$$?

Accepted Answer

Potassium sulfate

Question 17

What is the charge on the phosphate ion?

Accepted Answer

$$3-$$

Question 18

Which of the following is the correct formula for the compound formed between barium and nitrate ions?

Accepted Answer

$$\mathrm{Ba(NO_3$)_2}$$

Question 19

A compound contains $$27.3\%$$ carbon and $$72.7\%$$ oxygen by mass. What is its empirical formula?

Accepted Answer

$$\mathrm{CO_2$}$$

Question 20

How many moles of $$\mathrm{H_2O}$$ are present in $$36.0 g of $$water? (Molar mass $$= 18.0\ \mathrm{g/mol})$$

Accepted Answer

$$2.0$$ moles

Writing and Predicting Chemical Formulas, Nomenclature, and Stoichiometry

Study Guide - Practice Questions