Si la masa de una muestra de un compuesto Y es de 196 gramos y contiene 2 mol, la masa molar de Y es

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?