Question

10.5g of zinc trioxocarbonate(IV), were heated very strongly to a constant mass and the residue treated with excess hydrochloric acid. Calculate the mass of zinc chloride that would be obtained.

Answer 1

Answer:

m=13.6g

Explanation:

ZnCO3==> ZnO + CO2

ZnO + 2HCl ==> ZnCl2+ H2O

mols ZnCO3 = grams/molar mass = ?

1 mol ZnCO3 gives 1 mol ZnO

1 mol ZnO produces 1 mol ZnCl2.

grams ZnCl2 = mols ZnCl2 x molar mass ZnCl3.

ZnCO3+2HCl ==> ZnCl2+ H2O+CO2

1 mole of ZnCO3=1 mole of ZnCl2

1 mole =(10.5/125)

Therefore, (10.5/125 )×136

Mole=mass/molar mass

Mass = molar mass × mole

i.e. m =136 × 0.1

m = 13.6g