a sample of gas occupies a volume of 1025ml at 75C and 0.75atm. what will be the new volume if temperature decreases to 35C and pressure increases to 1.25atm?

Combined gas law is a law that combines both Boyle's law and Charles's law.
According to the combined gas law the volume of a fixed mas of a gas is directly proportional to absolute temperature but inversely proportional to pressure.

That is; [tex]\frac{P1V1}{T1} =\frac{P2V2}{T2}[/tex]

in our case we are given;

Initial volume, V1 = 1025 mL

Initial temperature, T1 = 75 °C (But K = °C + 273.5)

= 348.5 K

Initial pressure, P1 = 0.75 atm

New temperature, T2 = 308.15 K (35°C +273.15)

New pressure , P2 = 1.25 atm

We are required to calculate the new volume, V2

Replacing the known variables in the equation of combined gas law we can find the new volume;

[tex]V2=\frac{P1V1T2}{P2T1}[/tex]

[tex]=\frac{(1025mL)(0.75atm)(308.15K)}{(1.25atm)(248.15K)}[/tex]

[tex]=544.34mL[/tex]

Therefore, the new volume is 544.34 mL