The air in a cylinder of a diesel engine occupies 945 ml at 29oc and 1.00 atm. what is the pressure in the cylinder when the air is compressed to 67.5 ml and heats to 2000oc for an instant when the fuel explodes. what is the pressure of the gases in the cylinder at this instant before expansion occurs?

105 atm

Explanation:

1) Assuming ideal gases, use the combined law of gases

PV
= constant
 T

=>

P1 V1        P2 V2
= 
   T1             T2

2) Convert the temperature to absolute scale:

T1 = 29 + 273.15 K = 302.15 K
T2 = 2000 + 273.15 K = 2273.15 K

3) Replace the data and solve for P2

P2 = [P1 V1 / T1] [T2 / V2]

=> P2 = [1 atm 945 mL / 302.15 K ] [ 2273.15K / 67.5 mL] = 105 atm

105 atm

The teacher is mostly talking about the distillation of a mixture