(i) Tamished copper vessel has a layer of copper carbonate around it. On rubbing with lemon (which contains citric acid), a reaction takes place between the carbonate layer and citric acid. Carbonate layer is removed and the vessel shines again.
(ii) Alkalies are water soluble bases. As all bases are not soluble in water, therefore, we can say that all bases are not alkalies. However, all alkalies come under the general category of bases.
(iii) Honey-bee sting contains methanoic acid. On applying baking soda over the stung area, methanoic acid is neutralised and relief is felt.