GRE Subject Test: Chemistry : Other Statistics

Study concepts, example questions & explanations for GRE Subject Test: Chemistry

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Example Questions

Example Question #1 : Other Statistics

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Determine the percentage yield if the expected yield of  in the above reaction is 40.911 grams but the actual yield is 35.322 grams.

Possible Answers:

Correct answer:

Explanation:

In chemistry, percentage yield is a term used to quantify the efficiency of a chemical reaction. In order to calculate this quantity, the value for the actual yield and theoretical yield is needed. The actual yield is the amount of product obtained during a chemical reaction. The theoretical yield is the maximum amount of product possible to be obtain by a chemical reaction which is based on the amount of reactants used. Below is the formula needed to calculate the percentage yield.

Example Question #2 : Other Statistics

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0.0031 moles of  was reacted with 0.0071 moles of  giving an actual yield of 0.1733 grams of . What is the percent yield of this reaction?

Possible Answers:

Correct answer:

Explanation:

 is the limiting reactant because based on the equation,  and  react in a 1:1 mole ratio. However, there is 0.0040 moles more of  than  present. Therefore the amount of  produced is limited by the amount of  present in the reaction. Based on the equation, for every 1 mole of  reacted, 1 mole of  was produced:

Therefore,

 

Example Question #3 : Other Statistics

Screen shot 2016 02 27 at 6.20.58 pm

Determine the percentage yield if the expected yield of  in the above reaction is 1.2124 grams but the actual yield is 0.9749 grams.

Possible Answers:

Correct answer:

Explanation:

In chemistry, percentage yield is a term used to quantify the efficiency of a chemical reaction. In order to calculate this quantity, the value for the actual yield and theoretical yield is needed. The actual yield is the amount of product obtained during a chemical reaction. The theoretical yield is the maximum amount of product possible to be obtain by a chemical reaction which is based on the amount of reactants used. Below is the formula needed to calculate the percentage yield.

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