Which activity from following is exhibited by Lewis base according to definition?

Which of the following ion has greater coagulating power for negatively charged sol?

If enthalpy change for following reaction at $$300 \mathrm{~K}$$ is $$+7 \mathrm{~kJ} \mathrm{~mol}^{-1}$$ find the entropy change of surrounding?

$$\mathrm{H}_2 \mathrm{O}_{(\mathrm{s})} \longrightarrow \mathrm{H}_2 \mathrm{O}_{(\ell)}$$

Identify the polymer obtained from