Question

the pressure exerted by a gas in a container depends on..
a the tendency of the gas particles to dissolve in water.
b the space between the molecules.
c the instrument used to measure the pressure.
d the number of collisions between gas molecules and the walls container.

Explanation:

Step1: Analyze option A

The tendency of gas particles to dissolve in water is related to solubility, not pressure.

Step2: Analyze option B

The space between molecules is related to volume and density concepts, not directly to pressure.

Step3: Analyze option C

The instrument used to measure pressure is just a tool for quantification, not a factor determining pressure.

Step4: Analyze option D

According to the kinetic - molecular theory of gases, gas pressure is caused by the collision of gas molecules with the walls of the container. The more collisions per unit area, the higher the pressure.

Answer:

D. the number of collisions between gas molecules and the walls container.