Question

One way of obtaining pure sodium carbonate is through the decomposition of the mineral trona, Na3(CO3)(HCO3)·2H2O. 2Na3(CO3)(HCO3)·2H2O(s) → 3Na2CO3(s) + CO2(g) + 5H2O(g) When 1.00 metric ton (1.00 × 103 kg) of trona is decomposed, 0.650 metric ton of Na2CO3 is recovered. What is the percent yield of this reaction?

92.4%

72.1%

65.0%

48.1%

35.0%

Answer 1

moles of mineral trona = 1 x 10^3 kg/226.03 g/mol

                                     = 4.42 mol

moles of Na2CO3 formed (theoretical) = 4.42 x 3/2

                                                              = 6.64

Theoretical yield of Na2CO3 = 6.64 x 106

                                               = 703.45 g

percent yield = 0.650 x 10^3 x 100/703.45

                      = 92.4%