Edexcel IGCSE Chemistry Precise Observations

Edexcel IGCSE Chemistry Precise Observations
Edexcel IGCSE Chemistry syllabusChemistry 4CH1Issue 3 (2024)

Practise Edexcel IGCSE Chemistry precise observations by recognising colour, effervescence and gas syringe evidence during reactions.

How this is tested

  • State a solution colour accurately, such as blue for copper(II) sulfate solution.
  • Recognise that a reaction has stopped when fizzing ends or no more gas is collected.

Question 7(a)(iv)

[Maximum number: 1]

A student uses this apparatus to investigate the rate of reaction between dilute sulfuric acid and an excess of small pieces of zinc.

Figure for Question 7(a)(iv) — Edexcel IGCSE Chemistry

This is the student's method.
Step 1 use 50 cm350 \mathrm{~cm}^{3} of dilute sulfuric acid
Step 2 add approximately 5 g of small zinc pieces to the sulfuric acid
Step 3 quickly connect the gas syringe
Step 4 record the reading on the gas syringe every 30 seconds until the reaction stops

State how the student would know when the reaction stops.