A 1.15 mol sample of carbon monoxide gas has a temperature of 27°C and a pressure of 0.300 atm. If the temperature were lowered to 17°C, at constant volume, what would be the new pressure?

1 Answer
Oct 10, 2016

Answer:

The new pressure will be 0.29 atm .

Explanation:

This is an example of Gay-Lussac's gas law, which states that the pressure of a given amount of gas kept at constant volume is directly proportional to the temperature in Kelvins.

The equation for this gas law is #(P_1)/(T_1)=(P_2)/(T_2)#. Notice that the number of moles is not a variable in the equation. The number of moles was given to indicate that the #"1.15 mol CO"_2"# does not change, and is the "given amount of gas."

Determine the known and unknown values.

Known
#P_1="0.300 atm"#
#T_1="27"^@"C"+"273.15"="300 K"#
#T_2="17"^@"C"+"273.15"="290 K"#

Unknown
#P_2#

Solution
Rearrange the equation to isolate #P_2#. Substitute the known values into the equation and solve.

#P_2=(P_1T_2)/(T_1)#

#P_2=((0.300"atm")xx(290cancel"K"))/(300cancel"K")="0.29 atm"#