Electrolysis hydrocloric acid and both of the electrode uses a platinium what will happen to both of the electrode?

What is a metal replacement reaction

Avariable that is not being directly tested during an experiment should be

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?