Chemistry · States of Matter - Gases, Liquids and Solids
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What happens when the number of moles of the gas is doubled at a constant volume?
- A
Pressure doubles
- B
Pressure is reduced to 1/2
- C
Pressure is reduced to 1/4
- D
Pressure stays the same
According to the general gas equation, PV=nRT
If other factors are constant, then P is directly proportional to the number of moles
According to the ideal gas law, PV=nRT. If volume (V) and temperature (T) are constant, pressure (P) is directly proportional to the number of moles (n). Doubling the moles doubles the pressure.
This option is incorrect. Reducing pressure to half would require a reduction in moles or an increase in volume, but neither occurs here.
This is incorrect. Reducing pressure to 1/4 would imply a significant reduction in moles or a major increase in volume, neither of which is stated.
This option is incorrect. If the number of moles is doubled while keeping volume and temperature constant, pressure cannot remain unchanged.
Tagged under Chemistry · States of Matter - Gases, Liquids and Solids · 2005