ExpertEasy1 markShort Answer
AQA GCSE · Question 07.1 · The rate and extent of chemical change
A student investigated how concentration affects the rate of reaction between magnesium and hydrochloric acid. Figure 5 shows a gas syringe. What is the volume of gas in the syringe?
A student investigated how concentration affects the rate of reaction between magnesium and hydrochloric acid. Figure 5 shows a gas syringe. What is the volume of gas in the syringe?
How to approach this question
1. Identify the main numbered markings on the syringe scale (e.g., 80, 90).
2. Determine the value of the smaller markings between the numbers. The space between 80 and 90 is 10 cm³. There are 5 intervals, so each small line represents 10/5 = 2 cm³.
3. Locate the position of the plunger. It is on the third small line after 80.
4. Calculate the reading: 80 + (3 × 2) = 86 cm³.
Full Answer
The scale on the gas syringe is marked every 10 cm³. Between each number (e.g., between 80 and 90), there are five divisions. This means each small line represents 10 cm³ / 5 = 2 cm³.
The front of the plunger is located on the third small line after the 80 cm³ mark.
Therefore, the volume is 80 + (3 × 2) = 80 + 6 = 86 cm³.
Common mistakes
✗ Misreading the scale (e.g., thinking each small line is 1 cm³).
✗ Reading from the wrong end of the plunger.
Practice the full AQA GCSE Chemistry Foundation Tier Paper 2
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