Chapter 3: Chemical Formulae & Equations

The formula of sulphate salt of X is XSO₄. What is the formula of nitrate salt of X?

• XNO₃

• X₂NO₃

• X(NO₃)₂

• X₂(NO₃)₂

Calcium carbonate is a compound found in toothpaste. What is the chemical formulae of calcium carbonate?

• CaCO₃

• Ca₂CO₃

• Ca(CO₃)₂

• Ca₂(CO₃)₂

State the chemical formula for magnesium nitrate.

• MgNO₃

• Mg₂(NO₃)₂

• Mg(NO₃)₂

• Mg(NO)₃

Name the ionic compound for NH₄Cl.

• Ammonia chloride

• Ammonium chloride

• Ammonium(I) chloride

• Ammonium(IV) chloride

Balance the equation:

KI + Br_{2 -->} I₂ + KBr

• 2KI + Br₂ --> I₂ + KBr

• KI + Br₂ --> I₂ + 2KBr

• 2KI + Br₂ --> I₂ + 2KBr

• KI + Br_{2 -->} I₂ + KBr

Write a balanced chemical equation:

Nitrogen gas + Hydrogen gas --> Ammonia gas

• N₂ + H₂ --> 2NH

• N₂ + H₂ --> N₂H₂

• N₂ + H₂ --> NH₂

• N₂ + 3H₂ --> 2NH₃

Hot zinc metal will react with chlorine gas to produce solid zinc chloride. Write a balanced chemical equations for the reaction.

• Zn + Cl --> ZnCl

• Zn + Cl₂ --> ZnCl₂

• Zn + 2Cl --> ZnCl₂

• 2Zn + 2Cl --> 2ZnCl

Decomposition of hydrogen peroxide:

2H₂O₂ --> 2H₂O + O₂

_{What are the products of the decomposition?}

• hydrogen peroxide

• water

• water and oxygen gas

• oxygen gas