Question

If 30ml of hydrogen and 20 ml of oxygen reacts to form water what is left at the end of the reaction?

Answer 1

If 1 ml of hydrogen reacts with 0.5 ml of oxygen to form 1 ml of water. 30 ml of hydrogen will react with 15ml of oxygen to form water. So finally at the end 30 ml of water and 5ml of oxygen will be left.