Chemical Reactions Test Review

Use the activity series chart to predict the outcome of the single replacement reaction where magnesium metal is added to a solution of zinc nitrate.

Mg + Zn(NO₃)₂ →

• magnesium nitrate is formed

• gaseous magnesium is formed

• Zinc nitride is formed

Use the activity series chart to predict the outcome of the single replacement reaction where copper metal is added to a solution of sodium nitrate.

Cu + Na(NO₃)₂ →

• copper nitrate is formed

• gaseous copper is formed

• sodium nitride is formed

• no reaction occurs

In this double replacement reaction, when aqueous solutions of magnesium sulfate and barium chloride react, which substance will be the precipitate?

MgSO₄ + BaCl₂ → MgCl₂ + BaSO₄

• MgSO₄

• BaCl₂

• MgCl₂

• BaSO₄

According to the Activity Series, which equation represents a single replacement reaction that can occur?

Ba + HgCl₂ → Hg + BaCl₂

• I₂ + LiBr →Br₂ + LiI

• Cu + NaNO₃ → CuNO₃ + Na

• Au + KNO3 → AuNO₃ + K

• Ba + HgCl₂ → Hg + BaCl₂

Which of the following is the balanced equation that represents the reaction between lithium and oxygen to produce lithium oxide (written correctly)?

2Li + 2O → Li₂O₂

• Li + O → LiO

• 4Li + O₂ → 2Li₂O

• Li + O₂ → LiO₂

• 2Li + 2O → Li₂O₂

What must be balanced in order to have a balanced chemical equation?

• The total number of atoms of each element

• The total volume of all gases included in the reaction

• The total number of molecules or formula units of each compound

• All of the above

What occurs during a single-replacement reaction?

• One element replaces another element in a compound.

• Two elements replace each other in two compounds.

• One compound breaks apart into two or more component elements.

• Two elements combine to form a single compound.

Classify this reaction and identify its balanced equation.

C₃H₈(g) + O₂(g) →CO₂(g) + H₂O(g)

• Single Replacement

• Combustion

• Decomposition

• Double Replacement

After wood burns, the ash weighs much less than the original wood. Why is the law of conservation of mass not violated in this situation?

• The law of conservation of mass is violated.

• Wood ashes contain hidden mass that is not easily measured.

• Much of the matter of the wood combined with oxygen to form two gases: carbon dioxide and water.

• Much of the matter of the wood was absorbed into the ground or fireplace.

The chemical equation shown below is unbalanced.

_Fe + _H₂O → _Fe₃O₄ + _H₂

When the equation is balanced, what is the coefficient for Fe (iron)?

• 1

• 3

• 4

• 2