Which among the following salts exhibits inverse relation between it's solubility and temperature?

Which from following series of elements is correctly arranged according to their decreasing order of ionisation enthalpy $$\left(\mathrm{IE}_1\right)$$ ?

Identify the product formed by the action of $$\mathrm{H}_2(\mathrm{~g})$$ with $$\mathrm{CO}(\mathrm{g})$$ in presence of $$\mathrm{Ni}$$ ?

Calculate $$E^{\circ}$$ cell for following.

$$\mathrm{Zn}(s)\left|\mathrm{Zn}^{++}(1 \mathrm{M}) \| \mathrm{Pb}^{++}(1 \mathrm{M})\right| \mathrm{Pb}(s)$$ if $$E_{\mathrm{Zn}}^{\circ}=-0.763 \mathrm{~V}$$ and $$E_{\mathrm{Pb}}^{\circ}=-0.126 \mathrm{~V}$$