Edexcel IGCSE Chemistry Simple Algebraic Equations

Edexcel IGCSE Chemistry Simple Algebraic Equations
Edexcel IGCSE Chemistry syllabusChemistry 4CH1Issue 3 (2024)

Practise Edexcel IGCSE Chemistry simple algebraic equations by substituting rate values into reciprocal formulae for reaction time.

How this is tested

  • Solve time equals one divided by rate after reading or calculating the reaction rate.

Question 7(e)(ii)

[Maximum number: 2]

Dilute hydrochloric acid reacts with a solution of sodium thiosulfate (Na2 S2O3)\left(\mathrm{Na}_{2} \mathrm{~S}_{2} \mathrm{O}_{3}\right) to form a precipitate.

The equation for the reaction is

Na2 S2O3(aq)+2HCl(aq)→2NaCl(aq)+S( s)+H2O(l)+SO2( g)\mathrm{Na}_{2} \mathrm{~S}_{2} \mathrm{O}_{3}(\mathrm{aq})+2 \mathrm{HCl}(\mathrm{aq}) \rightarrow 2 \mathrm{NaCl}(\mathrm{aq})+\mathrm{S}(\mathrm{~s})+\mathrm{H}_{2} \mathrm{O}(\mathrm{l})+\mathrm{SO}_{2}(\mathrm{~g})

Calculate the time that it would take for the cross not to be seen at 45 °C.

time = ................................ s