[timchai]

It is predicted that sulphate(IV) ions can reduce vanadium(V) up to vanadium(III) under standard
conditions. However actually no further reaction occurs after vanadium(V) is reduced to
vanadium(IV) by the reagent. Give an explanation for this phenomenon. (1 mark)
ans :The reduction of vanadium(IV) to vanadium(III) is too slow to be observed, [1]
i.e. the reaction does not actually occur due to kinetic reason

i don't know wt is meant by kinetic reaction

i think the ans should be SO2+VO2 +---->VO 2+ due to SO2 evaporate and then escape ,shift eqm position ...Isn't it

[Astrokel]

Have you learnt kinetics?

[timchai]

i think kinetic is based on structure , for example  Why is it unlikely that the chemical reaction would proceed in one step as shown in Equation A H2O2 + 2H+ + 2I

2H2O + I2 because 5 particles collide , no low chamce ,and also in the formation of bromomethane lower chance , in HK AL exam , because it is surrounded by many H atom in C , so lower chance for bromine to attack

[Astrokel]

Yes you are right, it has to do with rate of reaction - how fast the reaction proceeds. Isn't measurable? Is the reaction speed practical? So what about kinetics that you don't get?

[timchai]

but i can't make me believe the anms, the speed is low .why .and also i think the ans should correspond to eqm as i said