Choose the incorrect statement :

${\mathrm{FeSO}}_4$ solution mixed with ${\left({\mathrm{NH}}_4\right)}_2{\mathrm{SO}}_4$ solution in 1: 1 molar ratio gives the test of ${\mathrm{Fe}}^{2+}\text{ ion }$

${\mathrm{CuSO}}_4$ solution mixed with aqueous ammonia in 1 : 1 molar ratio gives test of ${\mathrm{Fe}}^{2+}\text{ ion }$

Aq. ${\mathrm{CuSO}}_4$ solution (blue in colour) gives a green precipitate with aqueous potassium fluoride 

Aq. ${\mathrm{CuSO}}_4$ solution (blue in colour) gives a bright green solution with aqueous potassium chloride