Chemistry Past Questions and Answers

The colour changes observed when testing for reducing agents using acidified potassium heptaoxodichromate (IV) solution is

The oxidation state of Cr in K₂Cr₂O₇ is

Which of the following metals is purified commercially by electrolysis?

What current will deposit 3.25g of zinc in 2hrs?
[Zn = 65, F = 96500 mol^-]

C_(s) + H₂O_(g) → H_2(g) + CO_2(g)
ΔG for the reaction above at 1300k is -43KJ. At this temperature, the reaction is