Question

When we increase the temperature of the gas stored in a closed container,

• A. the number of molecules of gas increase.
• B. the speed and kinetic energy of the gas molecules increase.
• C. the most probable speed of the gas molecules increases.
• D. the number of molecules travelling at probable speed decrease.
• E. the pressure of the gas increases.

Answer 1

Answer: (B), (C), (D), (E)

the pressure of the gas increases.

As you can see the speed of the molecules increases with increase in temperature, so do the most probable speed. As the speed increases kinetic energy is bound to increase. But the number of molecules that are travelling with probable speed decreases (as you can see from the graph), the height of the curve of 100 K is more than the height of the curve of 1000 K.
But, the area under the curve of all the three temperatures remains same, that is nothing but the total number of molecules, hence they remain unchanged.
Moreover, we already learnt from ideal gas equation that as tempereture increases pressure will also increase, if volume is kept constant. So in this case, pressure increases.