QUESTION 3 (a) Write chemical equations which show what happens when the following substances are mixed with water: (i) Nitrous acid (ii) The hydride ion (iii) Potassium sulfate 3 (b) For each of the following chemical reactions, write a formula (molecular) equation, complete ionic equation and net ionic equation: O Magnesium hydroxide reacts with hydrobromic acid (ii) An alkali metal phosphate reacts with mercury(I) nitrate w