What is the final concentration of cl- ion when 250 ml of 0. 20 m cacl2 solution is mixed with 250 ml of 0. 40 m kcl solution? (assume additive volumes. ).

Alidded glass container is filled with a colored gas. after a period of time, it is observed that the gas is uniformly spread throughout the box and that the movement has slowed considerably. next, a warm iron plate is carefully placed under the box. why is there resumed movement of the gas in the container?