Magnesium reacts with sulfuric acid:
Mg(s) + H2SO4(aq) → MgSO4(aq) + H2(g)
The graph shows the results of an experiment using excess magnesium ribbon and dilutesulfuric acid.
Outline why the rate of the reaction decreases with time.
concentration of acid decreases
OR
surface area of magnesium decreases
Accept “less frequency/chance/rate/probability/likelihood of collisions”.
Do not accept just “less acid” or “lessmagnesium”.
Do not accept “concentrations ofreagents decrease”.
Sketch, on the same graph, the expected results if the experiment were repeatedusing powdered magnesium, keeping its mass and all other variables unchanged.
curve starting from origin with steeper gradient AND reaching same maximumvolume
Nitrogen dioxide and carbon monoxide react according to the following equation:
NO2(g) + CO(g) ⇌ NO(g) + CO2(g) Δ_H_ = –226 kJ
Calculate the activation energy for the reverse reaction.
«_E_a(rev) =226 +132 =» 358 «kJ»
Do not accept –358.