Question 1

Calculate the mass of sodium chlorate that must be decomposed to form 6.5 g of oxygen.
2NaClO3(s)$\rarr$2NaCl(s)+ 3O2(g)

Accepted Answer

Question 2

Ammonia reacts with diatomic oxygen to form nitric oxide and water vapor: 4NH3 + 5O2 $\rarr$ 4NO + 6H2O
When 40.0 g NH3 and 50.0 g O2 are allowed to react, which is the limiting reagent?

Accepted Answer

A) NH3 
B) O2 
C) NO 
D) H2O 
E) No reagent is limiting. 
A) NH3 
B) O2 
C) NO 
D) H2O 
E) No reagent is limiting.

Question 3

When a 0.860 g sample of an organic compound containing C, H, and O was burned completely in oxygen, 1.64 g of CO2 and 1.01 g of H2O were produced. What is the empirical formula of the compound?

Accepted Answer

Question 4

Balance the following chemical equation:
C + Fe2O3 $\rarr$ Fe + CO

Accepted Answer

Question 5

Calculate the mass of 4.50 moles of chlorine gas, Cl2.

Accepted Answer

A) 6.34 * 10-2 g 
B) 4.5 g 
C) 15.7 g 
D) 160 g 
E) 319 g 
A) 6.34 * 10-2 g 
B) 4.5 g 
C) 15.7 g 
D) 160 g 
E) 319 g

Question 6

The percent composition by mass of tartaric acid is: 32.01% C, 4.03% H, and 63.96% O.Given that the molecular mass of tartaric acid is 150 amu, determine its molecular formula.

Accepted Answer

The answer of The percent composition by mass of tartaric...

Question 7

Calculate the mass of 3.7 moles of Br2.

Accepted Answer

Question 8

Calculate the percent composition by mass of carbon in Na2CO3.

Accepted Answer

Question 9

A compound was discovered whose composition by mass is 85.6% C and 14.4% H.Which of the following could be the molecular formula of this compound?

Accepted Answer

A) CH4 
B) C2H4 
C) C3H4 
D) C2H6 
E) C3H8 
A) CH4 
B) C2H4 
C) C3H4 
D) C2H6 
E) C3H8

Question 10

Which of the following samples contains the greatest number of atoms?

Accepted Answer

A) 100 g of Pb 
B) 2.0 mole of Ar 
C) 0.1 mole of Fe 
D) 5 g of He 
E) 20 million O2 molecules 
A) 100 g of Pb 
B) 2.0 mole of Ar 
C) 0.1 mole of Fe 
D) 5 g of He 
E) 20 million O2 molecules

Question 11

Calculate the mass of 3.00 moles of CF2Cl2.

Accepted Answer

A) 3.00 g 
B) 174 g 
C) 363 g 
D) 1.81 * 1024 g 
E) 40.3 g 
A) 3.00 g 
B) 174 g 
C) 363 g 
D) 1.81 * 1024 g 
E) 40.3 g

Question 12

What is the coefficient of H2O when the following equation is properly balanced with smallest set of whole numbers?
 ___ Al4C3 + ___ H2O $\rarr$ ___ Al(OH)3 + ___ CH4

Accepted Answer

A) 3 
B) 4 
C) 6 
D) 12 
E) 24 
A) 3 
B) 4 
C) 6 
D) 12 
E) 24

Question 13

Common gases used in laboratories are generally obtained from pressurized metal gas cylinders, but for small amounts of occasionally-used gases, it is sometimes easier just to prepare them chemically.For example, oxygen gas can be prepared by heating KMnO4(s)according to the following chemical reaction:
2KMnO4(s)$\rarr$K2MnO4(s)+ MnO2(s)+ O2(g)
The above procedure was carried out starting with 93.2 g of KMnO4, and it was later determined that all of the KMnO4 reacted according to the above equation except 11.7 g.What was the percent yield for the reaction?

Accepted Answer

Question 14

What is the average mass, in grams, of one arsenic atom?

Accepted Answer

A) 5.48 * 10-23 g 
B) 33.0 g 
C) 74.9 g 
D) 1.24 * 10-22 g 
E) 8.04 * 1021 g 
A) 5.48 * 10-23 g 
B) 33.0 g 
C) 74.9 g 
D) 1.24 * 10-22 g 
E) 8.04 * 1021 g

Question 15

One nanogram does not seem like a very large number. How many magnesium atoms are there in 1.00 ng of magnesium?

Accepted Answer

A) 4.11 * 10-11 atoms 
B) 2.48 * 1013 atoms 
C) 6.83 * 10-35 atoms 
D) 6.02 * 1014 atoms 
E) 1.46 * 1034 atoms 
A) 4.11 * 10-11 atoms 
B) 2.48 * 1013 atoms 
C) 6.83 * 10-35 atoms 
D) 6.02 * 1014 atoms 
E) 1.46 * 1034 atoms

Question 16

Aluminum hydroxide reacts with nitric acid to form aluminum nitrate and water. What mass of water can be formed by the reaction of 15.0 g of aluminum hydroxide with excess nitric acid?

Accepted Answer

A) 1.15 g 
B) 3.46 g 
C) 45.0 g 
D) 6.14 g 
E) 10.4 g 
A) 1.15 g 
B) 3.46 g 
C) 45.0 g 
D) 6.14 g 
E) 10.4 g

Question 17

Balance the following equation using the smallest set of whole numbers, then add together the coefficients.Do not forget to count coefficients of one.The sum of the coefficients is __ SF4 + __ H2O $\rarr$ __ H2SO3 + __ HF

Accepted Answer

A) 4. 
B) 6. 
C) 7. 
D) 9. 
E) none of these. 
A) 4. 
B) 6. 
C) 7. 
D) 9. 
E) none of these.

Question 18

Ammonia reacts with diatomic oxygen to form nitric oxide and water vapor: 4NH3 + 5O2 $\rarr$ 4NO + 6H2O
When 20.0 g NH3 and 50.0 g O2 are allowed to react, which is the limiting reagent?

Accepted Answer

A) NH3 
B) O2 
C) NO 
D) H2O 
E) No reagent is limiting. 
A) NH3 
B) O2 
C) NO 
D) H2O 
E) No reagent is limiting.

Question 19

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 20

Balance the following chemical equation:
C3H6O + O2 $\rarr$CO2 + H2O

Accepted Answer

Exam 3: Mass Relationships in Chemical Reactions

Calculate the mass of sodium chlorate that must be decomposed to form 6.5 g of oxygen. 2NaClO3(s) →\rarr→ 2NaCl(s)+ 3O2(g)

Ammonia reacts with diatomic oxygen to form nitric oxide and water vapor: 4NH3 + 5O2 →\rarr→ 4NO + 6H2O When 40.0 g NH3 and 50.0 g O2 are allowed to react, which is the limiting reagent?

When a 0.860 g sample of an organic compound containing C, H, and O was burned completely in oxygen, 1.64 g of CO2 and 1.01 g of H2O were produced. What is the empirical formula of the compound?

Balance the following chemical equation: C + Fe2O3 →\rarr→ Fe + CO

Calculate the mass of 4.50 moles of chlorine gas, Cl2.

The percent composition by mass of tartaric acid is: 32.01% C, 4.03% H, and 63.96% O.Given that the molecular mass of tartaric acid is 150 amu, determine its molecular formula.

Calculate the mass of 3.7 moles of Br2.

Calculate the percent composition by mass of carbon in Na2CO3.

A compound was discovered whose composition by mass is 85.6% C and 14.4% H.Which of the following could be the molecular formula of this compound?

Which of the following samples contains the greatest number of atoms?

Calculate the mass of 3.00 moles of CF2Cl2.

What is the coefficient of H2O when the following equation is properly balanced with smallest set of whole numbers? ___ Al4C3 + ___ H2O →\rarr→ ___ Al(OH)3 + ___ CH4

What is the average mass, in grams, of one arsenic atom?

One nanogram does not seem like a very large number. How many magnesium atoms are there in 1.00 ng of magnesium?

Aluminum hydroxide reacts with nitric acid to form aluminum nitrate and water. What mass of water can be formed by the reaction of 15.0 g of aluminum hydroxide with excess nitric acid?

Balance the following equation using the smallest set of whole numbers, then add together the coefficients.Do not forget to count coefficients of one.The sum of the coefficients is __ SF4 + __ H2O →\rarr→ __ H2SO3 + __ HF

Ammonia reacts with diatomic oxygen to form nitric oxide and water vapor: 4NH3 + 5O2 →\rarr→ 4NO + 6H2O When 20.0 g NH3 and 50.0 g O2 are allowed to react, which is the limiting reagent?

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

Balance the following chemical equation: C3H6O + O2 →\rarr→ CO2 + H2O

Chemistry: The Study of Change

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Calculate the mass of sodium chlorate that must be decomposed to form 6.5 g of oxygen. 2NaClO₃(s) $\rarr$ 2NaCl(s)+ 3O₂(g)

Ammonia reacts with diatomic oxygen to form nitric oxide and water vapor: 4NH₃ + 5O₂ $\rarr$ 4NO + 6H₂O When 40.0 g NH₃ and 50.0 g O₂ are allowed to react, which is the limiting reagent?

When a 0.860 g sample of an organic compound containing C, H, and O was burned completely in oxygen, 1.64 g of CO₂ and 1.01 g of H₂O were produced. What is the empirical formula of the compound?

Balance the following chemical equation: C + Fe₂O₃ $\rarr$ Fe + CO

Calculate the mass of 4.50 moles of chlorine gas, Cl₂.

Calculate the mass of 3.7 moles of Br₂.

Calculate the percent composition by mass of carbon in Na₂CO₃.

Calculate the mass of 3.00 moles of CF₂Cl₂.

What is the coefficient of H₂O when the following equation is properly balanced with smallest set of whole numbers? _ Al₄C₃ + _ H₂O $\rarr$ _ Al(OH)₃ + _ CH₄

Balance the following equation using the smallest set of whole numbers, then add together the coefficients.Do not forget to count coefficients of one.The sum of the coefficients is SF₄ + H₂O $\rarr$ H₂SO₃ + HF

Ammonia reacts with diatomic oxygen to form nitric oxide and water vapor: 4NH₃ + 5O₂ $\rarr$ 4NO + 6H₂O When 20.0 g NH₃ and 50.0 g O₂ are allowed to react, which is the limiting reagent?

Balance the following chemical equation: C₃H₆O + O₂ $\rarr$ CO₂ + H₂O