Question

Predict if precipitation will occur when the following pair of solutions are mixed. What would the chemical equation be? 1. KNO3(aq) and MgCl2(aq) 2. NaOH(aq) and Fe(NO3)3 (aq)

Answer 1

see below

Explanation:

`K^+ and NO_3^_` are ions always soluble then they doesn't product any precipitation an no reaction too because they are inert ions. `NO_3^_` is an oxidant but it can't oxidize cloride
`Cl^-` is a weak reductant and it can precipitante only with `Pb^2+, Hg_2^(2+) , Ag^+`
for the second reaction you have:
`3NaOH + Fe(NO_3)_3= NaNO_3 + Fe(OH)_3` and you obtain a floccose precipitate of `Fe(OH)_3` red-brown. Fe^(3+) always gives a precipitant at pH >3