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Edexcel IGCSE Chemistry 3.15 rate practical

Edexcel IGCSE Chemistry 3.15 rate practical
Edexcel IGCSE Chemistry syllabusChemistry 4CH1First assessment 2019

Practise rate-practical questions by plotting mass loss, explaining graph shape and controlling marble chip and acid variables.

How this is tested

  • Plot mass-loss data and draw a best-fit curve that starts at the origin and levels off.
  • Explain curve shape using acid concentration decreasing as marble chips react.
  • Control mass and surface area of marble chips, acid volume and acid concentration.

Question 8

[Maximum number: 2]

A student uses this apparatus to investigate the rate of reaction between marble chips and dilute hydrochloric acid.

Figure for Question 8 — Edexcel IGCSE Chemistry

This is the equation for the reaction.

CaCO3( s)+2HCl(aq)→CaCl2(aq)+H2O(l)+CO2( g)\mathrm{CaCO}_{3}(\mathrm{~s})+2 \mathrm{HCl}(\mathrm{aq}) \rightarrow \mathrm{CaCl}_{2}(\mathrm{aq})+\mathrm{H}_{2} \mathrm{O}(\mathrm{l})+\mathrm{CO}_{2}(\mathrm{~g})

Question 8(a)

(a)

Give a reason why the reading on the balance decreases during the reaction.

[ 1 ]

Question 8(c)

(b)

After 10 minutes, the reaction stops even though there are marble chips remaining.

Give a reason why the reaction stops.

[ 1 ]