Click on the Increase/Decrease Moles and Increase/Decrease Temperature buttons at the left of the screen. The changes you make will cause the pressure to change while the volume remains constant. Temperature and moles have min/max limits set.
My first scratch. Allows the user to change observe changes in pressure when the temperature and moles are changed with a constant volume. Can be used as a teacher demo or as a student acitivity allowing them to collect data.