Review Stoichiometry Chemistry

Multiple ChoiceIdentify the choice that best completes the statement or answers the question.

1 How many moles of tungsten atoms are in 4.8

10 atoms of tungsten?A 8.0 10 molesB 8.0 10 molesC 1.3 10 molesD 1.3 10 moles

2 What is the molar mass of (NH ) CO ?A 144 gB 138 gC 96 gD 78 g

3 What is the number of moles of beryllium atoms in 36 g of Be?A 0.25 molB 4.0 molC 45.0 molD 320 mol

4 In every chemical reaction, ____.A mass and molecules are conservedB moles and liters are conservedC mass and atoms are conservedD moles and molecules are conserved

5 In the reaction 2CO(g) + O (g) 2CO (g), what is the ratio of moles of oxygen used to moles of

CO produced?A 1:1B 2:1C 1:2D 2:2

6 How many moles of aluminum are needed to react completely with 1.2 mol of FeO?

2Al(s) + 3FeO(s) 3Fe(s) + Al O (s)A 1.2 molB 0.8 molC 1.6 molD 2.4 mol

7 The equation below shows the decomposition of lead nitrate. How many grams of oxygen are

produced when 11.5 g NO is formed?

A 1.00 gB 2.00 gC 2.88 gD 32.0 g

8 How many grams of H PO are produced when

10.0 moles of water react with an excess of P O

?

A 1.22 gB 6.7 gC 147 gD 653 g

9 Which element has a molar mass of 30.974 g/mol?A PotassiumB PhosphorusC GalliumD Palladium

10 Which is the mass of 8 moles of sodium chloride?A 7.3 gramsB 468 gramsC 0.137 g/moleD 468 moles

11 How many molecules are in 3.6 grams of NaCl?A 0.06B 1.0 X 1021

C 1.3 x 1026

D 3.7 x 1022

12 How many grams are in 1.946 moles of NaCl?A 113.8 gB 30.1 gC 0.033 gD 44.7 g

13 Which is true of the reaction shown below?

A The mole ratio of this reaction is 6:5:6.B Two molecules of Substance Y will be left over when this reaction goes to completion.C Substance Y is the limiting reagent in this reaction.D The addition of more molecules of Substance X will not affect the amount of Substance Z

that can be made.14 Which is the correct mole ratio of K3PO4 to

KNO3 in the chemical reaction Mg(NO3)2 + K3PO4 Mg3(PO4)2 + KNO3?A 1:1B 2:3C 1:3D 1:2

15 How many moles of Cu are needed to react with 5.8 moles of AgNO3?Cu + 2 AgNO3 Cu(NO3)2 + 2 Ag

A 2.9 molesB 3.8 molesC 5.8 molesD 11.6 moles

16 How many grams of H2O will be produced if 750 grams of Fe are produced?

A 17.9 gB 322 gC 563 gD 241 g

CompletionComplete each statement.

17 Avogadro’s number ____________________ determines the volume of one mole of a gas.

18 The number of moles present in 165 g manganese is ____________________ mol.

Essay

19 Represent the reaction between nitrogen and hydrogen in terms of:a. Particlesb. Molesc. Mass

Review Stoichiometry ChemistryAnswer Section

MULTIPLE CHOICE

1 B2 C3 B4 C5 C6 B7 B8 D9 B

10 B11 D12 A13 B14 C15 A16 B

COMPLETION

1718 3.00

three

ESSAY

19 a. 1 molecule N2 + 3 molecules H2 2 molecules NH3

b. 1 mole N2 + 3 moles H2 2 moles NH3

c. 28.02 g N2 + 6.06 g H2 34.08 g NH3