10 ml of ammonia was enclosed in an eudiometer and subjected to electric sparks. The sparks were continued till there was no further increase in volume. The volume after sparking measured 20ml. Now 30ml of O2 were added and sparking was continued again. The new volume then measured 27.5ml. All volumes were measured under identical conditions of temperature and pressure. Calculate the molecular formula of ammonia. Nitrogen and Hydrogen are diatomic.