# Question 9bcb0

##### 1 Answer
Apr 27, 2014

The pressure gauge will read 12.4 atm.

What gas law should you use? Boyle's Law, Charles' Law, Gay-Lussac's Law, Avogadro's Law, the Combined Gas Laws, or the Ideal Gas Law?

Let's list what you know.

${P}_{1}$ = 12.0 atm; ${V}_{1}$ = 5.00 L; ${T}_{1}$ = 295 K
${P}_{2}$ = ?; ${V}_{2}$ = 5.00 L; ${T}_{2}$ = 308 K

The volume doesn't change, because the metal tank has a constant volume. You can ignore the volume change, because there is none.

The only variables are pressure and temperature. This is a Gay-Lussac's Law Problem (you could also use the Combined Gas Laws, since you know the volumes).

${P}_{1} / {T}_{1} = {P}_{2} / {T}_{2}$

P_2 = P_1 × T_2/T_1# = 12.0 atm × $\left(308 \text{ K")/(295" K}\right)$ = 12.5 atm.

The pressure in the tank is 12.5 atm.

This makes sense. We expect the pressure of a confined gas to increase as the temperature increases.