Bleaching powder is produced by the action of chlorine on dry slaked lime. Which of the following is the appropriate equation for this?

A

$$Ca (OH)_2 + 2Cl = CaOCl_2 + H_2O$$

B

$$Ca (OH)_2 + Cl = 2CaOCl_2 + H_2O$$

C

$$Ca (OH)_2 + Cl_2 = CaOCl_2 + H_2O$$

D

$$Ca (OH)_2 + Cl_2 = CaOCl_2 + 2H_2O$$