Rate of reaction helppp !!! heyy guys. I reallyy need help. I am doing my rate of reaction coursework ... nad i am stuck. I know there are three ways of measuring the rate of a reaction (right ? ) 1. weighing the reaction mixture 2. the cross 3. the gas displacement rightt ... in my coursework i am using Hydrochloric acid and sodium thiosulphate. I know that the cross method is the best ... because our teacher told us. But why does the weighing one not work ?? Hopeee you understand what i'm on about. Would be reallyy greatful for your replies. Thank youuu !!