Chapter 7 quiz

If oxygen molecules, O₂, were to react with magnesium atoms, how many electrons would each magnesium atom lose? How many electrons would each oxygen atom gain? How many magnesium atoms would be needed to react with each oxygen molecule? What charges would the resulting magnesium and oxide ions have?

Each magnesium atom would lose two electrons. Each oxygen atom would gain two electrons (so the O₂ molecule would gain four electrons). Two magnesium atoms would be required to react with each O₂ molecule. Magnesium ions are charged 2⁺, oxide ions are charged 2⁻.

For the reaction 2K + S → K₂S describe how electrons are gained and lost by the atoms.

Each potassium atom loses one electron. The sulfur atom gains two electrons. So two potassium atoms are required to react with one sulfur atom.

Fill in the blank _____ + _____ → K₂SO₄ + 2H₂O

H₂SO₄ + 2KOH

What are spectator ions?

Ions that remain in the solution after a chemical reaction

What is meant by strong base? Are strong bases also strong electrolytes?

Strong bases are hydroxide compounds whose ions separate completely in water. Strong bases are also strong electrolytes because their ions completely separate in water.

Label the type of reaction of this unbalanced equation C₃H₈ + O₂ → CO₂ + H₂O

combustion

Label the type of reaction of this unbalanced equation CaSO₄ → CaO + SO₃

decomposition

Label the type of reaction of this equation HCl + AgC₂H₃O₂ --> AgCl + HC₂H₃O₂

double displacement

What are some driving forces that tend to make chemical reactions likely to occur?

formation of a solid, formation of water, formation of a gas, and transfer of electrons

Label the type of reaction of this unbalanced equation CaO + H₂O → Ca(OH)₂

synthesis reaction