Classification of Chemical Reactions

Identify the oxidation number of the underlined element: Na₂S₂O₃

• 0

• +1

• +2

• +3

Identify the oxidation number of the underlined element: C₂O₄^-2

• 0

• +1

• +2

• +3

Identify the oxidation number of the underlined element: CuCl

• 0

• +1

• +2

• +3

Identify the oxidation number of the underlined element: I₂

• 0

• +1

• +2

• +3

What is the product of a synthesis reaction between solid potassium (K) and chlorine gas (Cl₂)?

• KCl

• K₂Cl

• PCl₂

As shown, a student added a small amount of sodium carbonate solution to a test tube containing calcium chloride solution. A white solid immediately appeared. What conclusion can be made from this experiment?

• The chemical reaction requires energy to occur.

• A precipitate was formed during the reaction.

• Heat is generated by the chemical reaction.

• Sodium carbonate is less soluble than calcium chloride.

Which of the following chemical reactions will produce a precipitate?

• Na₂CO₃ + CaCl₂  CaCO₃ + 2NaCl

• 3KBr + AlPO₄  K₃PO₄ + AlBr₃

• NH₄OH + KCl   KOH + NH₄Cl

• ZnCl₂ + MgSO₄  ZnSO₄ + MgCl₂

Which is not an example of a redox reaction?

• 2Mg(s) + O₂(g) 2MgO(s)

• 2HgO(aq) + Cl₂(g) 2HgCl(aq) + O₂(g)

• CH₄(g) + 2O₂(g) CO₂(g) + 2H₂O(g)

• CuCl₂(aq) + H₂S(aq) CuS(s) + 2HCl(aq)

What are the coefficients that balance the following equation?

___ PbO₂ ___ PbO + ___ O₂

• 4, 3, 2

• 2, 2, 1

• 3, 4, 2

• 2, 1, 1

What type of reaction is the following?

___ PbO₂ ___ PbO + ___ O₂

• Decomposition

• single replacement

• combustion

• Synthesis