question_answer

  A compound which is prepared from gypsum has the property of hardening when mixed with proper quantity of water. (a) Identify the compound. (b) Write the chemical equation for its preparation. (c) Mention one important use of this compound.

Answer:

                  (a) When baking powder is added to the mixture during cake preparation, the baking soda present in it, produces gas on heating, which makes the cake soft and spongy.                           (b) The  gas produced by the reaction of baking soda and acid in the soda-acid fire extinguisher, helps in extinguishing fire.      (1) (c) pH value of baking soda solution is higher than 7, i.e., it is alkaline.                                (1)