IGCSE · Practice questions · Experimental design and apparatus

Measure it right.

Six original Cambridge-style questions on apparatus, solution vocabulary and improving an experiment.

Original questions All questions on this page are original work, written in the Cambridge IGCSE style. They are not from past papers. They test the same concepts and skills the syllabus rewards.

Keep these straight

Quantity, apparatus, precision.

Time: stopwatch. Temperature: thermometer. Mass: balance.
Volume: burette (variable), volumetric pipette (fixed), measuring cylinder (rough), gas syringe (gas).
Solvent dissolves solute to give a solution.
Residue stays in the filter paper; filtrate passes through.

Recall

[4 marks]

Name the apparatus used to measure (a) time, (b) temperature, (c) mass and (d) the volume of a gas.

(a) stopwatch (or stop-clock). ✓
(b) thermometer. ✓
(c) electronic balance. ✓
(d) gas syringe. ✓

Recall

[2 marks]

Define the terms solute and saturated solution.

Solute: the substance that is dissolved in a solvent. ✓
Saturated solution: a solution containing the maximum concentration of solute dissolved in the solvent at a specified temperature. ✓

Analysis

[2 marks]

A mixture of chalk and water is filtered. Name the residue and the filtrate.

Residue: chalk (calcium carbonate), left in the filter paper. ✓
Filtrate: water, which passes through the paper. ✓

Explain

[2 marks]

Explain why a volumetric pipette, not a measuring cylinder, is used to measure 25.0 cm³ of alkali for a titration.

A volumetric pipette delivers a fixed volume much more accurately. ✓
Titration results are only as accurate as the volume of alkali used, so the least precise step must be avoided. ✓

Analysis

[3 marks]

A student measures the temperature rise when magnesium is added to acid in a glass beaker, using a thermometer reading to 1 °C. Suggest two improvements and explain each.

Use a polystyrene cup with a lid instead of a glass beaker. ✓
This reduces heat lost to the surroundings, so the temperature rise is more accurate. ✓
Use a thermometer reading to 0.1 or 0.5 °C, giving more precise readings. ✓

Explain

[2 marks]

A student collects ammonia over water to measure its volume. Explain why this method is unsuitable and suggest a better one.

Ammonia is very soluble in water, so most of it dissolves and the measured volume is far too low. ✓
Collect the gas in a gas syringe instead. ✓

Mark this once you have attempted all six and checked your working. It records a Practiced badge on the topic and adds a one-time bonus. Revealing the solutions alone does not count.