Question 1

How many sodium atoms are there in 6.0 g of Na3N?

Accepted Answer

A) 3.6 × 1024 atoms 
B) 4.6 × 1022 atoms 
C) 1.3 × 1023 atoms 
D) 0.22 atoms 
E) 0.072 atoms 
A) 3.6 × 1024 atoms 
B) 4.6 × 1022 atoms 
C) 1.3 × 1023 atoms 
D) 0.22 atoms 
E) 0.072 atoms

Question 2

What is the molecular mass of Br2 ?

Accepted Answer

A) 79.90 amu 
B) 79.90 g 
C) 159.8 amu 
D) 159.8 g 
E) 2.65 x 10-22 amu 
A) 79.90 amu 
B) 79.90 g 
C) 159.8 amu 
D) 159.8 g 
E) 2.65 x 10-22 amu

Question 3

How many moles of CF4 are there in 171 g of CF4?

Accepted Answer

A) 0.51 mol 
B) 1.94 mol 
C) 4.07 mol 
D) 88.0 mol 
E) 171 mol 
A) 0.51 mol 
B) 1.94 mol 
C) 4.07 mol 
D) 88.0 mol 
E) 171 mol

Question 4

The mineral orpiment, having the empirical formula As2S3, was used in ancient times as a cosmetic.What mass of arsenic is present in 5.0 g of orpiment? [Given: naturally occurring arsenic is all arsenic-75; assume that all naturally occurring sulfur is sulfur-32 (only approximately true)]

Accepted Answer

A) 0.61 g 
B) 3.0 g 
C) 1.5 g 
D) 2.0 g 
E) 3.5 g 
A) 0.61 g 
B) 3.0 g 
C) 1.5 g 
D) 2.0 g 
E) 3.5 g

Question 5

How many moles of phosphine (PH3 )are produced for every 4.0 moles of hydrogen that react according to the chemical equation below?
3H2 + P2 $\rarr$ 2PH3

Accepted Answer

Question 6

Calculate the percent composition by mass of sodium in Na2CO3.

Accepted Answer

Question 7

The mineral hausmannite is a compound of 55Mn and 16O.If 72% of the mass of hausmannite is due to manganese, what is the empirical formula of hausmannite?

Accepted Answer

A) MnO 
B) Mn3O 
C) Mn3O4 
D) Mn4O3 
E) MnO3 
A) MnO 
B) Mn3O 
C) Mn3O4 
D) Mn4O3 
E) MnO3

Question 8

Iron metal reacts with hydrochloric acid to produce iron (II)chloride and hydrogen gas.Identify the balanced reaction that describes this process.

Accepted Answer

A) Fe + 2 HCl $\rarr$FeCl2 + H2 
B) Fe + HCl $\rarr$ FeCl2 + H2 
C) Fe + HCl $\rarr$ FeCl + H 
D) 2Fe + 2HCl $\rarr$2FeCl2 + H2 
E) Fe + 3HCl $\rarr$FeCl3 + H2 
A) Fe + 2 HCl $\rarr$FeCl2 + H2 
B) Fe + HCl $\rarr$ FeCl2 + H2 
C) Fe + HCl $\rarr$ FeCl + H 
D) 2Fe + 2HCl $\rarr$2FeCl2 + H2 
E) Fe + 3HCl $\rarr$FeCl3 + H2

Question 9

Calculate the number of moles of cesium in 50.0 g of cesium.

Accepted Answer

A) 0.376 mol 
B) 0.357 mol 
C) 2.66 mol 
D) 2.80 mol 
E) 0.0200 mol 
A) 0.376 mol 
B) 0.357 mol 
C) 2.66 mol 
D) 2.80 mol 
E) 0.0200 mol

Question 10

A 1.375 g sample of mannitol, a sugar found in seaweed, is burned completely in oxygen to give 1.993 g of carbon dioxide and 0.9519 g of water.The empirical formula of mannitol is

Accepted Answer

A) CHO 
B) CH7O3 
C) C3H2O 
D) C3H7O3 
E) CH2O 
A) CHO 
B) CH7O3 
C) C3H2O 
D) C3H7O3 
E) CH2O

Question 11

One way of obtaining pure sodium carbonate is through the decomposition of the mineral trona, Na 3(CO3)(HCO3)$\rarr$2H2O, as shown in the following reaction: 2Na3(CO3)(HCO3).2H2O(s)$\rarr$3Na2CO3(s)+ CO2(g)+ 5H2O(g)
When 15 metric tons (1 × 103 kg)of trona is decomposed, 11 metric tons of Na2CO3 is recovered.What is the percent yield of this reaction? (1 metric ton = 103 kg)

Accepted Answer

A) 13% 
B) 42% 
C) 65% 
D) 73% 
E) 95% 
A) 13% 
B) 42% 
C) 65% 
D) 73% 
E) 95%

Question 12

Calculate the molar mass, in g/mol, of Fe2(CO3)3.

Accepted Answer

Question 13

A compound with a percent composition by mass of 24.61% C, 2.75% H, and 72.64% Cl has a molar mass of 292.82 g/mol.What is the molecular formula of the compound?

Accepted Answer

The answer of A compound with a percent composition by...

Question 14

Calculate the molar mass of (NH4)2SO4

Accepted Answer

A) 114.11 g/mol 
B) 228.22 g/mol 
C) 118.14 g/mol 
D) 63.09 g/mol 
E) 132.15 g/mol 
A) 114.11 g/mol 
B) 228.22 g/mol 
C) 118.14 g/mol 
D) 63.09 g/mol 
E) 132.15 g/mol

Question 15

Calculate the molecular mass, in g/mol, of C6H12O6.

Accepted Answer

Question 16

How many O atoms are there in 51.4 g CaSO4?

Accepted Answer

A) 4.00 
B) 2.40 × 1024 
C) 1.13 
D) 9.09 × 1023 
E) 2.28 × 1023 
A) 4.00 
B) 2.40 × 1024 
C) 1.13 
D) 9.09 × 1023 
E) 2.28 × 1023

Question 17

Calculate the mass of 4.50 moles of Ca3PO4

Accepted Answer

A) 215 g 
B) 968 g 
C) 0.0209 g 
D) 87.1 g 
E) 392 g 
A) 215 g 
B) 968 g 
C) 0.0209 g 
D) 87.1 g 
E) 392 g

Question 18

Determine the number of moles of aluminum in 96.7 g of Al.

Accepted Answer

A) 0.279 mol 
B) 3.58 mol 
C) 7.43 mol 
D) 4.21 mol 
E) 6.02 × 1023 mol 
A) 0.279 mol 
B) 3.58 mol 
C) 7.43 mol 
D) 4.21 mol 
E) 6.02 × 1023 mol

Question 19

The Hall process for the production of aluminum involves the reaction of aluminum oxide with elemental carbon to give aluminum metal and carbon monoxide.If the yield of this reaction is 75%, what mass of aluminum metal can be produced from the reaction of 1.65 × 106 g of aluminum oxide with 1.50 × 106 g of carbon?

Accepted Answer

A) 1.6 × 105 g 
B) 1.7 × 106 g 
C) 3.3 × 105 g 
D) 6.6 × 105 g 
E) 8.7 × 105 g 
A) 1.6 × 105 g 
B) 1.7 × 106 g 
C) 3.3 × 105 g 
D) 6.6 × 105 g 
E) 8.7 × 105 g

Question 20

A sample of aluminum metal is placed in a graduated cylinder.It is noted that 5.50 mL of water is displaced by the aluminum.The aluminum is then reacted with excess nitric acid to produce aluminum nitrate and hydrogen gas.Given the density for aluminum is 2.702 g/mL, how many grams of aluminum nitrate are produced in the reaction? 2Al(s)+ 6HNO3(aq)$\rarr$ 2Al(NO3)3(aq)+ 3H2(g)

Accepted Answer

A) 161 g 
B) 11.0 g 
C) 14.9 g 
D) 117 g 
E) 235 g 
A) 161 g 
B) 11.0 g 
C) 14.9 g 
D) 117 g 
E) 235 g

Exam 3: Mass Relationships in Chemical Reactions

How many sodium atoms are there in 6.0 g of Na3N?

What is the molecular mass of Br2 ?

How many moles of CF4 are there in 171 g of CF4?

The mineral orpiment, having the empirical formula As2S3, was used in ancient times as a cosmetic.What mass of arsenic is present in 5.0 g of orpiment? [Given: naturally occurring arsenic is all arsenic-75; assume that all naturally occurring sulfur is sulfur-32 (only approximately true)]

How many moles of phosphine (PH3 )are produced for every 4.0 moles of hydrogen that react according to the chemical equation below? 3H2 + P2 →\rarr→ 2PH3

Calculate the percent composition by mass of sodium in Na2CO3.

The mineral hausmannite is a compound of 55Mn and 16O.If 72% of the mass of hausmannite is due to manganese, what is the empirical formula of hausmannite?

Iron metal reacts with hydrochloric acid to produce iron (II)chloride and hydrogen gas.Identify the balanced reaction that describes this process.

Calculate the number of moles of cesium in 50.0 g of cesium.

A 1.375 g sample of mannitol, a sugar found in seaweed, is burned completely in oxygen to give 1.993 g of carbon dioxide and 0.9519 g of water.The empirical formula of mannitol is

Calculate the molar mass, in g/mol, of Fe2(CO3)3.

A compound with a percent composition by mass of 24.61% C, 2.75% H, and 72.64% Cl has a molar mass of 292.82 g/mol.What is the molecular formula of the compound?

Calculate the molar mass of (NH4)2SO4

Calculate the molecular mass, in g/mol, of C6H12O6.

How many O atoms are there in 51.4 g CaSO4?

Calculate the mass of 4.50 moles of Ca3PO4

Determine the number of moles of aluminum in 96.7 g of Al.

Chemistry: the Study of Change

Atoms, Molecules, and Ions

Reactions in Aqueous Solutions

Gases

Thermochemistry

Quantum Theory and the Electronic Structure of Atoms

Periodic Relationships Among the Elements

Chemical Bonding I: Basic Concepts

Chemical Bonding Ii: Molecular Geometry and Hybridization of Atomic Orbitals

Intermolecular Forces and Liquids and Solids

Physical Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Entropy Free Energy and Equilibrium

Electrochemistry

Nuclear Chemistry

Chemistry in the Atmosphere

Metallurgy and the Chemistry of Metals

Nonmetallic Elements and Their Compounds

Transition Metal Chemistry and Coordination Compounds

Organic Chemistry

Synthetic and Natural Organic Polymers

Filters

How many sodium atoms are there in 6.0 g of Na₃N?

What is the molecular mass of Br₂ ?

How many moles of CF₄ are there in 171 g of CF₄?

The mineral orpiment, having the empirical formula As₂S₃, was used in ancient times as a cosmetic.What mass of arsenic is present in 5.0 g of orpiment? [Given: naturally occurring arsenic is all arsenic-75; assume that all naturally occurring sulfur is sulfur-32 (only approximately true)]

How many moles of phosphine (PH₃)are produced for every 4.0 moles of hydrogen that react according to the chemical equation below? 3H₂ + P₂ $\rarr$ 2PH₃

Calculate the percent composition by mass of sodium in Na₂CO₃.

The mineral hausmannite is a compound of ⁵⁵Mn and ¹⁶O.If 72% of the mass of hausmannite is due to manganese, what is the empirical formula of hausmannite?

Calculate the molar mass, in g/mol, of Fe₂(CO₃)₃.

Calculate the molar mass of (NH₄)₂SO₄

Calculate the molecular mass, in g/mol, of C₆H₁₂O₆.

How many O atoms are there in 51.4 g CaSO₄?

Calculate the mass of 4.50 moles of Ca₃PO₄