Practice questions: Percentage yield and atom economy

Carbon is used to extract tin (Sn) from tin oxide (SnO2). The equation for the reaction is:

SnO2 + C → Sn + CO2

Calculate the percentage atom economy for extracting tin in this reaction.

Relative atomic masses (Ar):

C = 12 O = 16 Sn = 119

A student wanted to make 11.0 g of copper chloride.

The equation for the reaction is:

CuCO3 + 2HCl → CuCl2 + H2O + CO2

Relative atomic masses, Ar:

H = 1; C = 12; O = 16; Cl = 35.5; Cu = 63.5

Calculate the mass of copper carbonate the student should react with dilute hydrochloric acid to make 11.0 g of copper chloride.

The equation for the reaction of copper carbonate and sulfuric acid is:

CuCO3 + H2SO4 → CuSO4 + H2O + CO2 Relative formula masses :

CuCO3 = 123.5; H2SO4 = 98.0; CuSO4 = 159.5

Calculate the percentage atom economy for making copper sulfate from copper carbonate.

An equation for the reaction is:

NiO + C ⟶ Ni + CO

Calculate the percentage atom economy for the reaction to produce nickel.

Relative atomic masses (Ar): C = 12 Ni = 59 Relative formula mass (Mr): NiO = 75

Give your answer to 3 significant figures