What would you observe in the following cases? (i) Sulphur trioxide is dissolved in water on a large scale. (ii) Concentrated sulphuric acid is added to equal volumes of cold water. (iii) 100 ml of 98% sulphuric acid is kept open. (iv) Hot concentrated sulphuric acid is added to sodium chloride crystals. (v) Dilute sulphuric acid is added to ferrous sulphate solution.