Unit 7 Review (Castle Learning)

Which type of reaction occurs when a compound is separated into its elements?

• synthesis

• decomposition

• single replacement

• double replacement

Which equation represents a single replacement reaction?

• 2Al(s) + 3Cl₂(g) → 2AlCl₃(s)

• 2Al(s) + 6HCl(aq) → 2AlCl₃(aq) + 3H₂(g)

• 2AlCl₃(s) → 2Al(s) + Cl₂(g)

• AlCl₃(aq) + 3KOH(aq) → Al(OH)₃(s) + 3KCl(aq)

What is the percent composition by mass of nitrogen in the compound N₂H₄ (gram-formula mass = 32 g/mol)?

• 13%

• 44%

• 88%

• 93%

How many moles of carbon dioxide are produced when 5.0 moles of butane react completely?

• 5.0 mol

• 10. mol

• 20. mol

• 40. mol

During all chemical reactions, charge, mass and energy are

• condensed

• conserved

• decayed

• decomposed

Given the reaction: 2KClO₃(s) → 2KCl(s) + 3O₂(g) How many moles of KClO₃ must completely react to produce 6 moles of O₂?

• 1 mole

• 2 moles

• 6 moles

• 4 moles

Given the equation representing a chemical reaction:

NaCl(aq) + AgNO₃(aq) → NaNO₃(aq) + AgCl(s)

This reaction is classified as a

• synthesis reaction

• decomposition reaction

• single replacement reaction

• double replacement reaction

Given the equation representing a reaction: Mg(s) + 2HCl(aq) → MgCl₂(aq) + H₂(g) Which type of chemical reaction is represented by the equation?

• synthesis

• decomposition

• single replacement

• double replacement

Given the balanced equation representing a reaction:

2NO + O₂ → 2NO₂ + energy

The mole ratio of NO to NO₂ is

• 1 to 1

• 2 to 1

• 3 to 2

• 5 to 2

What is the gram-formula mass of Ca(OH)₂?

• 29 g/mol

• 54 g/mol

• 57 g/mol

• 74 g/mol