Question

Consider

2SO2 (g) + O2 (g) = 2SO3 (g)

If 275.0 of SO2 is allowed to react with 159.0 ml of O2 ( both measured at 315 K and 53.2 mmHg ) what is the theoretical yield of SO3 ?

If 172.6 ml of SO3 is collected ( measured at 315 K and 53.2 mmHg ) what is the percent yield of the reaction?

Answer 1

Data.

P = 53.2 mmHg = 0.07 atm

T = 315 K

R = 0.082 atm.L/mol.K

theoretical yield of SO₃ = ??

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172.6 g SO₃ is observed.

% yield = ??

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Theory.

Theoretical yield for a reaction is calculated based on the limiting reagent. This allows us to determine how much product can be formed from reagents initially present at the reaction. A reaction should theoretically produce as much of the product as the stoichiometric ratio of product to the limiting reagent suggests. However, the amount of product actually produced by the reaction will usually be less than the theoretical yield and is referred to as the actual yield.

% yield = (actual yield/theoretical yield) x 100

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Answer.

2SO₂ (g) + O₂ (g) <==> 2SO₃ (g)

275 g SO₂ x 1mol SO₂ /64.006g SO2 x 2mol SO₃/2 mol SO₂ x 86.006 g SO₃/mol SO₃

theoretical yield = 369.52 g SO₃

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The Theoretical yield for SO₃ is 369.52 g and 172.6 g for actual yield was collected, percent yield can be calculated as;

% yield = 172.6 g SO₃/369.52 g SO₃x 100

% yield = 46.71

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