What happens when carbonic acid reacts with sodium hydroxide? Share with your friends Share 0 Ravjot Kaur answered this Dear student. When carbonic acid reacts with sodium, it forms sodium carbonate and hydrogen. The reaction is - H2CO3 +2Na----=Na2CO3 + H2. Regards 0 View Full Answer Mahi Aggarwal answered this hope 2 0 Mahi Aggarwal answered this it helps* 0