Answer:
956 mmHg
Step-by-step explanation:
The combined gas law states that P1V1/T1 = P2V2/T2 when moles of gas are constant. We're looking for P2, so solve all of that for P2. Make sure you convert your temperatures to Kelvin by adding 273 to the Celsius temperatures.
P2 = P1V1T2/T1V2
P1 = 800.00 mmHg
V1 = 5.0 L
T2 = 100 + 273 = 373 K
T1 = -50 + 273 = 223 K
V2 = 7.0 L
P2 = (800.00 mmHg)(5.0 L)(373 K) / (223 K)(7.0 K) = 956 mmHg