Question detail

Case 46 ratio-step. A balanced equation is used in a calculation. Which interpretation is safest? Focus on amount moles gas volume room temperature and in Gas volumes and amount of substance, not on a neighbouring Unit 4.3 idea.

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

Use of amount of substance in relation to volumes of gases (chemistry only) (HT only)

Question

A. Case 46 ratio-step: Use coefficients as mole-ratio information, not formula subscripts for amount moles gas volume room temperature and
B. Case 46 ratio-step: Treat subscripts inside a formula as reacting mole ratios (Gas volumes and amount of substance)
C. Case 46 ratio-step: Assume every reactant and product always has a 1 to 1 ratio (amount moles gas volume room temperature and)
D. Case 46 ratio-step: Use the largest mass as the limiting amount without mole comparison (Use of amount of substance in relation to volumes of gases (chemistry only) (HT only))

Answer

The correct option is Case 46 ratio-step: Use coefficients as mole-ratio information, not formula subscripts for amount moles gas volume room temperature and.

Explanation

The correct option is Case 46 ratio-step: Use coefficients as mole-ratio information, not formula subscripts for amount moles gas volume room temperature and. It supports the approved learning objective by keeping the method tied to amount moles gas volume room temperature and in Gas volumes and amount of substance. The other options are incorrect because they either use the wrong quantitative relationship, lose the required unit, confuse coefficients with subscripts, or report an answer without a complete worked method.

Common mistake

Confusing Volume and Moles

Students often confuse the volume of a gas with the amount in moles, forgetting that they need to use the relationship that 1 mole of gas occupies 24 dm3 at room temperature and pressure.

To fix this, remember to use the formula: moles = volume / 24 dm3 when calculating the amount in moles from gas volume.

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For Gas volumes and amount of substance, which option best supports this Unit 4.3 objective: (chemistry only) (HT only) Calculate amount in moles from gas volume at room temperature and pressure?