Question

An open flask of air is heated, stoppered in the heated condition, and then allowed to cool back to room temperature. Does the flask contain the same, more, or fewer gas molecules now compared to before it was heated? Is the volume occupied by the gas in the flask approximately the same, greater, or less than before it was heated? Is the pressure in the flask the same, greater, or less than before the flask was heated? Do any of the above conditions explain why water rushed into the flask lower temperature in the experiment? Amplify your answer.

Answer 1

Answer :- **** The flask contains fewer gas molecules now than it had before it was heated. The reason is that heating the flask causes the gas molecules inside it to heat up, and as they heat up, each gas molecule takes up more volume. Pressure increases, but without a stopper, gas simply leaks out of the flask a decrease in the amount of gas molecules present.
*****When the stopper is placed over the opening and the flask removed from the heat, everything starts to cool down. As the gas molecules cool, pressure decreases, but there is no way for gas to re-enter the flask. Thus the flask is trapped with less gas molecules than before.
The volume occupied by the gas in each instance is the same - the volume of the flask does not change. The pressure in the flask is lower after it was stoppered and cooled, as mentioned before.
Finally, do any of the above conditions explain why water rushed into the flas at the lower temp? Well, you didn't mention the water, or the events and conditions surrounding its possible entry into the flask, so...all I can say is that reduced pressure inside the flask would create a vacuum there, and if water were to be introduced to this system then it certainly would get sucked into the flask