Q. Which of the following pairs are correctly matched?

1. Bleaching powder – Oxidising agent in chemical industries
2. Baking powder – A mixture of sodium hydrogen carbonate and a mild edible acid
3. Washing soda – Used to remove permanent hardness of water

Select the correct answer using the codes given below:
Answer: 1, 2 and 3
Notes: Bleaching powder is used as an oxidising agent in chemical industries. Baking powder is a mixture of sodium hydrogen carbonate and a mild edible acid such as tartaric acid. Washing soda (sodium carbonate) is used to remove permanent hardness of water by precipitating out calcium and magnesium ions. Thus, all the pairs are correctly matched.