Question

Calculate the equilibrium constant for each of the reactions at 25 ∘C.
A) 2Fe3+(aq)+3Sn(s)→2Fe(s)+3Sn2+(aq)
B) O2(g)+2H2O(l)+2Sn2+(aq)→4OH−(aq)+2Sn4+(aq)

Answer 1

Remember

aA +bB -> cC + dD gives K (often easily remembered as PORK - product over reactant = K)
\[K = \frac{ [C]^c[D]^d }{ [A]^a[B]^b }\]

Note that solids are not included in the formula so you will exclude iron, for instance.

Answer 2

you can not calculate anything if you dont have the concentrations