A 32.1 L metal cylinder at [tex]29^{\circ} C[/tex] is filled with an ideal gas at 15.2 atm.

What is the pressure (in atm) in the cylinder if it is heated to [tex]105^{\circ} C[/tex]?

[tex]R = 0.082 \, L \cdot atm / K \cdot mol[/tex]

[tex] \text{Temperature (in K) = Temperature (in } ^{\circ} C) + 273[/tex]

A. 19.7
B. 4.2
C. 12.1
D. 55.0
E. 19.0



Answer :

Let's solve this problem step-by-step using the provided information and the Ideal Gas Law.

Given:
- Initial volume ([tex]\( V_1 \)[/tex]) = 32.1 L (Constant volume, hence [tex]\( V_1 = V_2 \)[/tex])
- Initial temperature ([tex]\( T_1 \)[/tex]) = [tex]\( 29^{\circ} C \)[/tex]
- Initial pressure ([tex]\( P_1 \)[/tex]) = 15.2 atm
- Final temperature ([tex]\( T_2 \)[/tex]) = [tex]\( 105^{\circ} C \)[/tex]
- Universal Gas Constant ([tex]\( R \)[/tex]) = 0.082 L atm / K mol (though not needed explicitly here)

First, convert the given temperatures from Celsius to Kelvin:
[tex]\[ T_1 = 29 + 273 = 302 \, \text{K} \][/tex]
[tex]\[ T_2 = 105 + 273 = 378 \, \text{K} \][/tex]

Since the volume remains constant and we are dealing with an ideal gas, we use the relationship derived from the Ideal Gas Law:
[tex]\[ \frac{P_1}{T_1} = \frac{P_2}{T_2} \][/tex]

Rearranging the equation to solve for the final pressure [tex]\( P_2 \)[/tex]:
[tex]\[ P_2 = P_1 \times \frac{T_2}{T_1} \][/tex]

Now, substitute the known values:
[tex]\[ P_2 = 15.2 \, \text{atm} \times \frac{378 \, \text{K}}{302 \, \text{K}} \][/tex]

Calculate [tex]\( P_2 \)[/tex]:
[tex]\[ P_2 = 15.2 \times 1.2516556291390728 \][/tex]
[tex]\[ P_2 \approx 19.025165562913905 \, \text{atm} \][/tex]

Rounding to one decimal place, the final pressure in the cylinder is:
[tex]\[ P_2 \approx 19.0 \, \text{atm} \][/tex]

So, the correct answer is:
[tex]\[ \boxed{19.0} \][/tex]