Question 1

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

Accepted Answer

$$0.50$$ moles

Question 2

Which of the following correctly represents Avogadro’s number?

Accepted Answer

$$6.02 	imes 10$$^{23}$$

Question 3

What is the molar mass of sodium sulfate ($$\mathrm{Na_2SO_4}$$)? (Atomic masses: Na = $$22.99 g/$$mol, S = $$32.07 g/$$mol, O = $$16.00 g/$$mol)

Accepted Answer

$$142.05 g/$$mol

Question 4

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

Accepted Answer

$$\mathrm{CH_2O}$$

Question 5

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

Accepted Answer

Iron(III) chloride

Question 6

What is the mass percent of oxygen in $$\mathrm{H_2SO_4}$$? (Atomic masses: H = $$1.01 g/$$mol, S = $$32.07 g/$$mol, O = $$16.00 g/$$mol)

Accepted Answer

$$65.2\%$$

Question 7

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

Accepted Answer

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

Question 8

A $$10.0 g $$sample of glucose ($$\mathrm{C_6H_{12}O_6$}) is $$combusted in excess oxygen. What mass of carbon dioxide ($$\mathrm{CO_2$}) is $$produced? (Molar mass of glucose = $$180.16 g/$$mol)

Accepted Answer

$$14.7 g$$

Question 9

Which of the following is the correct name for $$\mathrm{$$CuSO_4$$ \cdot 5H_2O}$$?

Accepted Answer

Copper(II) sulfate pentahydrate

Question 10

Balance the following equation: $$\mathrm{C_2H_6} + \mathrm{O_2$} \rightarrow \mathrm{CO_2$} + \mathrm{H_2O}. $$What are the correct coefficients?

Accepted Answer

$$2, 7, 4, 6$$

Question 11

A $$5.00 g $$sample of magnesium reacts with hydrochloric acid according to $$\mathrm{Mg} + 2\mathrm{HCl} \rightarrow \mathrm{$$MgCl_2$$} + \mathrm{H_2$}. $$How many moles of $$\mathrm{H_2$}$$ are produced? (Mg = $$24.31 g/$$mol)

Accepted Answer

$$0.103$$ moles

Question 12

Which of the following is the correct formula for the polyatomic ion sulfate?

Accepted Answer

$$\mathrm{SO_4$^{2-}}$$

Question 13

A $$20.0 g $$sample of calcium chloride ($$\mathrm{$$CaCl_2$$}) is $$dissolved in water. How many chloride ions are present? (CaCl$$_2$$ molar mass = $$110.98 g/$$mol, Avogadro’s number = $$6.02 	imes 10$$^{23}$$)

Accepted Answer

$$2.17 	imes 10$$^{23}$$

Question 14

Which of the following is the correct name for $$\mathrm{N_2O_4}$$?

Accepted Answer

Dinitrogen tetroxide

Question 15

A $$15.0 g $$sample of potassium nitrate ($$\mathrm{$$KNO_3$$}) $$contains how many moles of potassium? (Molar mass of KNO$$_3$$ = $$101.10 g/$$mol)

Accepted Answer

$$0.148$$ moles

Question 16

Which of the following is the correct formula for the polyatomic ion nitrate?

Accepted Answer

$$\mathrm{NO_3$^{-}}$$

Question 17

A $$12.0 g $$sample of sodium phosphate ($$\mathrm{Na_3PO_4}) is $$dissolved in water. How many sodium ions are present? (Molar mass of Na$$_3PO$_4$$ = $$163.94 g/$$mol, Avogadro’s number = $$6.02 	imes 10$$^{23}$$)

Accepted Answer

$$1.32 	imes 10$$^{23}$$

Question 18

Which of the following is the correct name for $$\mathrm{P_2O_5}$$?

Accepted Answer

Diphosphorus pentoxide

Question 19

A $$25.0 g $$sample of aluminum reacts with oxygen to form aluminum oxide ($$\mathrm{Al_2O_3}). $$How many grams of aluminum oxide are produced? (Al = $$26.98 g/$$mol, Al$$_2O$_3$$ = $$101.96 g/$$mol)

Accepted Answer

$$47.2 g$$

General Chemistry I Exam 2 Study Guide: Chapters 2–4

Guida di studio - Domande di pratica

Study guide - Flashcard