Need !
if the temperature of a gas is increased by 4x, what will happen to the volume?
a. it will increase by 4x.
b. it will decrease by -4
c. it will increase +4
d. it will decrease 1/4.

if the pressure of a gas is decreased by 4x, what will happen to the volume?
a. it will increase by 4x.
b. it will decrease by -4
c. it will increase +4
d. it will decrease 1/4.

1. If the temperature of a gas is increased by 4x, its volume A. will increase by 4x.

2. If the pressure of a gas is decreased by 4x, its volume A. will increase by 4x.

The combined gas law combines the three gas laws; Boyle's law, Charles law and Gay Lussac's law together relating pressure, temperature & volume and states thus:

"The ratio of product of Pressure and Volume to that of its Temperature is a constant."

In mathematical terms,

where P1, V1, T1 are the initial values and P2, V2, T2 the final values.

Therefore,

.......................................(1)

......................................(2)

1. If temperature of gas is increased by 4x, keeping pressure constant, from(1) since the volume of gas is directly proportional to its temperature (by Charles' law); it will increase in the same rate as  the temperature is increased. Hence, the volume will increase by 4x.

2. If the pressure of a gas is decreased by 4x, keeping temperature constant, from (2), since the pressure of a gas is inversely in proportion to its volume (by Boyles' law), a decrease in pressure leads to increase in volume and vice versa. Hence, the volume will increase by 4x.