Chemistry I - Quiz II

• 0.128

• 7.936

• 0.02

• 0.992

• 1.024

When the equation below is balanced, the correct set of stoichiometric coefficients will be________.

? Cu(s) + ? HNO₃(aq) → ? Cu(NO₃)₂(aq) + ? H₂O(l) + ? NO(g)

• 1, 6, 1, 3, 4

• 1, 3, 8, 2, 4

• 3, 8, 3, 4, 2

• 1, 4, 1, 2, 2

• 2, 6, 2, 3, 2

What is the empirical formula of a compound that contains 85.7% carbon and 14.3% hydrogen by mass?

• CH₃

• C₂H₃

• CH

• C₃H₆

• CH₂

What is the percent composition by mass of hydrogen in methane (CH₄)?

(Atomic weight of C=12, H=1 g/mol)

• 12.50%

• 50.00%

• 20.00%

• 25.00%

• 33.33%

How many moles of ammonia (NH₃) are produced when 3 moles of nitrogen gas react with 9 moles of hydrogen gas?

• 3 moles

• 15 moles

• 6 moles

• 9 moles

• 12 moles

Tags

NGSS.HS-PS1-7

How many moles of carbon dioxide are produced when 5 moles of propane (C₃H₈) are completely combusted?

• 5 moles

• 10 moles

• 15 moles

• 20 moles

• 25 moles

What is the percent composition by mass of nitrogen in ammonium nitrate (NH₄NO₃)?

(Atomic weight of N=14, H=1, O=16 g/mol)

• 52.50%

• 58.33%

• 42.00%

• 35.00%

• 28.00%

Which of the following is the balanced equation for the reaction of aluminum with oxygen to form aluminum oxide?

• 4 Al + 3 O₂ → 2 Al₂O₃

• 2 Al + O₂ → Al₂O₃

• Al + O₂ → AlO₂

• 3 Al + 2 O₂ → Al₃O₄

• 2 Al + 3 O₂ → 2 AlO₃

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-7

Which of the following is the balanced equation for the reaction of iron with oxygen to form iron(III) oxide?

• 2 Fe + O₂ → Fe₂O₃

• 4 Fe + 3 O₂ → 2 Fe₂O₃

• Fe + O₂ → FeO

• 2 Fe + 3 O₂ → 2 FeO₃

• 3 Fe + 2 O₂ → Fe₃O₄

Tags

NGSS.HS-PS1-2

An aqueous solution that is 5.30% LiBr by mass has a density of 1.040 g/mL. What is the molarity of this solution?

(Atomic weight of Li=7 and Br=80 g/mol)

• 0.0563 M

• 12.0 M

• 0.0635 M

• 0.563 M

• 0.635 M

Tags

NGSS.HS-PS1-5