Calculate the empirical for the molecular formula mass and the molar mass of each of the following minerals:

(a) Limestone, CaCO3

(b) halite, NaCl

(c) beryl, Be3Al2Si6O18

(d) malachite, Cu2 (OH) 2CO3

(e) turquoise, CuAl6 (PO4) 4 (OH) 8 (H2O) 4

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) Limestone, CaCO₃

Molar mass of the atoms are -

Calcium, Ca = 40 g / mol

Carbon, C = 12 g/mol

Oxygen, O = 16 g/mol

Molecular mass of CaCO₃ = (40 g / mol) + (12 g/mol) + (3 * 16 g/mol) = 100 g/mol.

(b) halite, NaCl

Molar mass of the atoms are -

Sodium, Na = 23 g/mol

Chlorine, Cl = 35.5

Molecular mass of NaCl = 23 + 35.5 = 58.5 g/mol.

(c) beryl, Be₃Al₂Si₆O₁₈

Molar mass of the atoms are -

Beryllium, Be = 9 g/mol

Aluminum, Al = 27 g/mol

Silicon, Si = 28 g/mol

Oxygen, O = 16 g/mol

Molecular mass of Be₃Al₂Si₆O₁₈ = (3 * 9) + (2*27) + (6 * 28) + (18 * 16) = 537 g/mol.

(d) malachite, Cu₂ (OH) ₂CO₃

Molar mass of the atoms are -

Copper, Cu = 63.5 g/mol

Oxygen, O = 16 g/mol

Carbon, C = 12 g/mol

hydrogen, H = 1 g / mol

Molecular mass of Cu₂ (OH) ₂CO₃ = (2 * 63.5) + (5 * 16) + (2 * 1) + (1 * 12) = 221 g/mol.

(e) turquoise, CuAl₆ (PO₄) ₄ (OH) ₈ (H₂O) ₄

Copper, Cu = 63.5 g/mol

Aluminum, Al = 27 g/mol

Phosphorous, P = 31 g/mol

Oxygen, O = 16 g/mol

hydrogen, H = 1 g / mol

Molecular mass of CuAl₆ (PO₄) ₄ (OH) ₈ (H₂O) ₄ =

(63.5*1) + (6 * 27) + (4 * 31) + (28 * 16) + (16 * 1) = 813 g/mol.