Question

Use the periodic table to calculate the molar mass of each of the following compounds. Give your answer to the correct number of significant figures. Ammonia (NH3): g/mol Lead(II) chloride (PbCl2): g/mol Acetic acid (CH3COOH): g/mol

Answer 1

Ammonia (NH3): ⇒ 17.04 g/molLead(II) chloride (PbCl2): ⇒ 278.10 g/mol

Acetic acid (CH3COOH): ⇒ 60.06 g/mol

Answer 2

1) Answer is: molar mas of ammonia is 17.031 g/mol.

M(NH₃) = Ar(N) + 3 · Ar(H) · g/mol.

M(NH₃) = 14.007 + 3 · 1.008 · g/mol.

M(NH₃) = 17.031 g/mol.

2) Answer is: molar mas of lead(II) chloride is 278.106 g/mol.

M(PbCl₂) = Ar(Pb) + 2 · Ar(Cl) · g/mol.

M(PbCl₂) = 207.2 + 2 · 35.453 · g/mol.

M(PbCl₂) = 278.106 g/mol.

3) Answer is: molar mas of acetic acid is 60.052 g/mol.

M(CH₃COOH) = 2 · Ar(C) + 2 · Ar(O) + 4 · Ar(H) · g/mol.

M(CH₃COOH) = 2 · 12.0107 + 2 · 15.9994 + 4 · 1.008 · g/mol.

M(CH₃COOH) = 60.052 g/mol.