Calculate the Molecular or Formula massof each of the following:

(a) P4

(b) H2O

(c) Ca (NO3) 2

(d) CH3CO2H (acetic acid)

(e) C12H22O11 (sucrose, cane sugar).

Molar mass

The mass present in one mole of a specific species.

The molar mass of a compound, can easily be calculated as the sum of the all the individual atom multiplied by the number of total atoms.

(a) P₄

Molar mass of of the atoms are -

Phosphorous, P = 31 g/mol

Molecular mass of P₄ = (4 * 31) = 124 g/mol.

(b) H₂O

Molar mass of of the atoms are -

Hydrogen, H = 1 g/mol

oxygen, O = 16 g/mol.

Molecular mass of H₂O = (2 * 1) + (1 * 16) = 18 g/mol

(c) Ca (NO₃) ₂

Molar mass of of the atoms are -

calcium, Ca = 40 g/mol

nitrogen, N = 14 g/mol

oxygen, O = 16 g/mol.

Molecular mass of Ca (NO₃) ₂ = (1 * 40) + (2 * 14) + (6 * 16) = 164 g/mol.

(d) CH₃CO₂H (acetic acid)

Molar mass of of the atoms are -

Carbon, C = 12 g/mol.

oxygen, O = 16 g/mol.

Hydrogen, H = 1 g/mol

Molecular mass of CH₃CO₂H = (2 * 12) + (2 * 16) + (4 * 1) = 60 g/mol.

(e) C₁₂H₂₂O₁₁ (sucrose, cane sugar).

Molar mass of of the atoms are -

Carbon, C = 12 g/mol.

oxygen, O = 16 g/mol.

Hydrogen, H = 1 g/mol

Molecular mass of C₁₂H₂₂O₁₁ = (12 * 12) + (22 * 1) + (11 * 16) = 342 g/mol.