calculate the theoretical and percent yields of Ag2CO3

Question

if 400 g of silver are reacted with an excess of magnesium (ii) carbonate, MgCO3, then magnesium and 0.00956 Kg of silver (i) carbonate are obtained. calculate the theoretical and percent yields of Ag2CO3

Answer 1

In this case, I believe there may be an error in the question because silver is below magnesium in the activity series of metals. This means it is not able to replace magnesium, and so there will be NO REACTION between Ag and MgCO₃.

Answer 2

The reaction between silver and MgCO₃ is:

2Ag + MgCO₃ → Ag₂CO₃ + Mg

Use stoichiometry to calculate the theoretical yield by converting g of Ag to g of Ag₂CO₃. Mole ratio of Ag to Ag₂CO₃ is 2:1. Molar mass of Ag and Ag₂CO₃ are 107.87 g/mol and 275.75 g/mol, respectively.

400 g Ag x (1 mol Ag / 107.87 g Ag) x (1 mol Ag₂CO₃ / 2 mol Ag) x (275.75 g Ag₂CO₃ / 1 mol Ag₂CO₃) = 511 g Ag₂CO₃

Actual yield of Ag₂CO₃ = 0.00956 kg x (1000 g / 1 kg) = 9.56 g

%-Yield = (Actual yield / Theoretical yield) x 100%

= (9.56 / 511) x 100% = 1.87%