Which salt is used as a purgative?

$A$ compound $(A)$ is used in the preparation of washing soda to recover ammonia in the Solvay process. When $CO_2$ is bubbled through an aqueous solution of $(A)$,the solution turns milky. It is used in whitewashing due to its disinfectant nature. What is the chemical formula of $(A)$?

The complex formation tendency of alkaline earth metals decreases down the group because

Which of the following gives a green color in the flame test?

Water is periodically sprinkled on cement plasters during curing. What does this help in?

The correct order of density for the alkaline earth metals is: