A gas has a volume of 1400 milliliters at a temperature of 20 K and a pressure of 1.0 atm. What will be the new volume when the temperature is changed to 40 K and the pressure is changed to 0.50 atm?​

5.6 L or 5600 mL

Explanation:

This question asks for the use of combined gas law:

(P1)(V1) / (T1) = (P2)(V2) / (T2)

...where pressure (P) is in atm, volume (V) is in liters, and temperature (T) is in kelvin.

1400 ml is 1.4 L, and everything else is already in the right units.

(1 atm)(1.4 L) / (20 K) = (0.5 atm)(V2) / (40 K)

Just solve the equation for V2, and you get a new volume of 5.6 liters.

(1)(1.4) / (20) = (.5x) / (40)

1.4 / 20 = .5x / 40

2.8 = .5x

x = 5.6