Question

which of the following will decrease the pressure of a gas in a closed container?
a increasing the amount of light
b increasing the volume
c increasing the number of molecules
d increasing the temperature

Explanation:

According to Boyle's Law, \(P_1V_1 = P_2V_2\) (at constant temperature and amount of gas). When the volume \(V\) increases, the pressure \(P\) decreases.

• Option A: Light has no direct relation to gas pressure in a closed container based on gas laws.
• Option C: Increasing the number of molecules (at constant volume and temperature) would increase pressure (Avogadro's Law \(V = kn\) at constant \(P\) and \(T\), but if \(V\) is constant, more \(n\) leads to higher \(P\)).
• Option D: Increasing temperature (at constant volume and amount of gas) would increase pressure (Gay - Lussac's Law \(P = kT\) at constant \(V\) and \(n\)).

Answer:

B. increasing the volume