CHEMICAL FORMULAE – MOLECULAR FORMULA• Ionic compounds are compounds made up of ions.• Ions are atoms or groups of atoms with positive or negative charges on them.• Positive ions are called cations. Examples include the

sodium ion, Na+ and the ammonium ion, NH4+.

• Negative ions are called anions. Examples include the chloride ion, CI- , and the carbonate ion, CO3

2 -.

CHEMICAL FORMULAE

CHEMICAL FORMULAE

CHEMICAL FORMULAE

CHEMICAL FORMULAE

CHEMICAL FORMULAE

CHEMICAL FORMULAE

CHEMICAL FORMULAE

CHEMICAL FORMULAE

CHEMICAL EQUATIONS

CHEMICAL EQUATIONS - SOLUTIONS

CHEMICAL EQUATIONS – PROBLEM SOLVING

CHEMICAL EQUATIONS – PROBLEM SOLVING

Solution:(a)2 moles of Na react with 1 mole of CI2.1 mole of Na will react with ⅟2 moles of Cl2

Hence 0.2 moles of Na will react with ⅟2 x 0.2 = 0.1 mole of Cl2.(b) Molar mass of Cl2 = 2 x 35.5 = 71 g mol- 1

Number of moles of Cl2=1.42/71 = 0.02 moles1 mole of Cl2 reacts with 2 moles of Na, 0.02 moles of CI2 will react with 0.02 x 2 = 0.04 mole of Na.Therefore, mass of Na = 0.04 x Ar of Na = 0.04 x 23 = 0.92 g.