This question is about nickel and compounds of nickel.
A student produces pure crystals of nickel(II) sulfate by reacting nickel(II) oxide with sulfuric acid.
The equation for the reaction is: NiO(s)+H2SO4(aq)→NiSO4(aq)+H2O(l)\text{NiO(s)} + \text{H}_2\text{SO}_4\text{(aq)} \rightarrow \text{NiSO}_4\text{(aq)} + \text{H}_2\text{O(l)}NiO(s)+H2SO4(aq)→NiSO4(aq)+H2O(l)
The student adds nickel(II) oxide to sulfuric acid until the nickel(II) oxide is in excess. Give one observation that the student could make to show that the nickel(II) oxide is in excess.
Why is excess nickel(II) oxide used rather than excess sulfuric acid?
Name one other nickel compound that the student could add to sulfuric acid to produce nickel(II) sulfate.
Describe how the student should obtain crystals of nickel(II) sulfate from a solution of nickel(II) sulfate.
Nickel(II) sulfate is also produced in a displacement reaction between nickel and copper(II) sulfate solution.
The equation for the reaction is: Ni+CuSO4→NiSO4+Cu\text{Ni} + \text{CuSO}_4 \rightarrow \text{NiSO}_4 + \text{Cu}Ni+CuSO4→NiSO4+Cu
Complete the ionic equation for this displacement reaction: Ni+‾→Ni2++‾\text{Ni} + \underline{\qquad\qquad} \rightarrow \text{Ni}^{2+} + \underline{\qquad\qquad}Ni+→Ni2++
Why is nickel described as being oxidised in this reaction?