Question 1

Calculate the number of moles in 17.8 g of the antacid magnesium hydroxide, Mg(OH)2.

Accepted Answer

A)  3.28 mol 
B)  2.32 mol 
C)  0.431 mol 
D)  0.305 mol 
E)  0.200 mol

Question 2

How many protons are there in a molecule of adrenaline (C9H13NO3), a neurotransmitter and hormone?

Accepted Answer

A)  22 
B)  26 
C)  43 
D)  98 
E)  183

Question 3

How many molecules of molecular oxygen react with four molecules of NH3 to form four molecules of nitrogen monoxide and six molecules of water?

Accepted Answer

A)  2 
B)  10 
C)  3 
D)  4 
E)  5

Question 4

Hydroxylamine hydrochloride is a powerful reducing agent which is used as a polymerization catalyst. It contains 5.80 mass % H, 20.16 mass % N, 23.02 mass % O, and 51.02 mass % Cl. What is its empirical formula?

Accepted Answer

A)  H2N7O8Cl18 
B)  H2N2O2Cl 
C)  HN3O4Cl9 
D)  H4NOCl 
E)  H4NOCl2

Question 5

Calculate the number of oxygen atoms in 29.34 g of sodium sulfate, Na2SO4.

Accepted Answer

A)  1.244 × 1023 O atoms 
B)  4.976 × 1023 O atoms 
C)  2.409 × 1024 O atoms 
D)  2.915 × 1024 O atoms 
E)  1.166 × 1025 O atoms

Question 6

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

Accepted Answer

A)  50.0 g of Li2O 
B)  75.0 g of CaO 
C)  200.0 g of Fe2O3 
D)  50.0 g of CO2 
E)  100.0 g of SO3

Question 7

Calculate the mass in grams of 8.35 × 1022 molecules of CBr4.

Accepted Answer

A)  0.0217 g 
B)  0.139 g 
C)  7.21 g 
D)  12.7 g 
E)  46.0 g

Question 8

Calculate the molar mass of tetraphosphorus decaoxide, P4O10, a corrosive substance which can be used as a drying agent.

Accepted Answer

A)  469.73 g/mol 
B)  283.89 g/mol 
C)  190.97 g/mol 
D)  139.88 g/mol 
E)  94.97 g/mol

Question 9

Constitutional (structural) isomers have the same molecular formula but different structural formulas.

Accepted Answer

A) True 
 B)False

Question 10

Ammonia will react with fluorine to produce dinitrogen tetrafluoride and hydrogen fluoride (used in production of aluminum, in uranium processing, and in frosting of light bulbs). 2NH3(g) + 5F2(g) → N2F4(g) + 6HF(g)
How many moles of NH3 are needed to react completely with 13.6 mol of F2?

Accepted Answer

A)  34.0 mol 
B)  27.2 mol 
C)  6.80 mol 
D)  5.44 mol 
E)  2.27 mol

Exam 3: Stoichiometry of Formulas and Equations

Calculate the number of moles in 17.8 g of the antacid magnesium hydroxide, Mg(OH) ₂.

How many protons are there in a molecule of adrenaline (C₉H₁₃NO₃) , a neurotransmitter and hormone?

How many molecules of molecular oxygen react with four molecules of NH₃ to form four molecules of nitrogen monoxide and six molecules of water?

Hydroxylamine hydrochloride is a powerful reducing agent which is used as a polymerization catalyst. It contains 5.80 mass % H, 20.16 mass % N, 23.02 mass % O, and 51.02 mass % Cl. What is its empirical formula?

Calculate the number of oxygen atoms in 29.34 g of sodium sulfate, Na₂SO₄.

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

Calculate the mass in grams of 8.35 × 10²² molecules of CBr₄.

Calculate the molar mass of tetraphosphorus decaoxide, P₄O₁₀, a corrosive substance which can be used as a drying agent.

Constitutional (structural) isomers have the same molecular formula but different structural formulas.

Exam 3: Stoichiometry of Formulas and Equations

Calculate the number of moles in 17.8 g of the antacid magnesium hydroxide, Mg(OH) 2.

How many protons are there in a molecule of adrenaline (C9H13NO3) , a neurotransmitter and hormone?

How many molecules of molecular oxygen react with four molecules of NH3 to form four molecules of nitrogen monoxide and six molecules of water?

Hydroxylamine hydrochloride is a powerful reducing agent which is used as a polymerization catalyst. It contains 5.80 mass % H, 20.16 mass % N, 23.02 mass % O, and 51.02 mass % Cl. What is its empirical formula?

Calculate the number of oxygen atoms in 29.34 g of sodium sulfate, Na2SO4.

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

Calculate the mass in grams of 8.35 × 1022 molecules of CBr4.

Calculate the molar mass of tetraphosphorus decaoxide, P4O10, a corrosive substance which can be used as a drying agent.

Constitutional (structural) isomers have the same molecular formula but different structural formulas.

Ammonia will react with fluorine to produce dinitrogen tetrafluoride and hydrogen fluoride (used in production of aluminum, in uranium processing, and in frosting of light bulbs) . 2NH3(g) + 5F2(g) → N2F4(g) + 6HF(g) How many moles of NH3 are needed to react completely with 13.6 mol of F2?

Calculate the number of moles in 17.8 g of the antacid magnesium hydroxide, Mg(OH) ₂.

How many protons are there in a molecule of adrenaline (C₉H₁₃NO₃) , a neurotransmitter and hormone?

How many molecules of molecular oxygen react with four molecules of NH₃ to form four molecules of nitrogen monoxide and six molecules of water?

Calculate the number of oxygen atoms in 29.34 g of sodium sulfate, Na₂SO₄.

Calculate the mass in grams of 8.35 × 10²² molecules of CBr₄.

Calculate the molar mass of tetraphosphorus decaoxide, P₄O₁₀, a corrosive substance which can be used as a drying agent.