A small amount of methyl orange is introduced into a reaction mixture. As the reaction proceeds, a gas is given off and the methyl orange changes from red to orange. Which substances are the reactants?
- Aaqueous sodium hydroxide and ammonium chloride
- Baqueous sodium hydroxide and calcium carbonate
- Cdilute hydrochloric acid and magnesium
- Ddilute hydrochloric acid and aqueous sodium hydroxide