Question detail

Calculate the percentage yield if 15 g of product was obtained from a theoretical yield of 25 g.

Try the question, check the answer, then read the explanation to understand the curriculum point.

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At a glance

MCQ

Type

practice

Style

Topic

Mathematical requirements and assessment objectives

Question

A. 60%
B. 50%
C. 70%
D. 80%

Answer

60%

Explanation

The correct option is 60%. Use Percentage Yield: percentage yield = (actual yield / theoretical yield) x 100. The worked result is 60 %. 60% is the best answer because it directly supports the AQA A-Level Chemistry objective to rearrange equations and use algebra in physical chemistry. This reasoning is anchored to Mathematical requirements in Mathematical requirements and assessment objectives, and it separates algebra from similar A-Level ideas rather than relying on a vague recall statement. Other options are weaker if they use the wrong evidence, calculation, mechanism, observation, unit, or conclusion for this subtopic.

Common mistake

Rearranging Equations Mistake

Students often forget to isolate the variable correctly when rearranging equations, leading to incorrect results.

To fix this, always perform the same operation on both sides of the equation to maintain equality. For example, if you need to rearrange the equation for concentration (c = m/V) to find volume (V), you would multiply both sides by V and then divide by c: V = m/c. This ensures the variable is isolated correctly.

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