Question

The pressure, P, of a gas varies directly with its temperature, T, and inversely with its volume, V, according to the equation P=nRT/V, where n is the number of molar units and R is the universal gas constant. One molar unit of gas has a pressure of about 1,245 joules at a temperature of 300 degrees Kelvin and a volume of 2 liters. What is the pressure of the same number of molar units of the gas at a temperature of 400 degrees Kelvin and a volume of 2.5 liters?

Answer 1

To solve this one. let use the formula of the Ideal Gas Law which is P=nRT/V.

 Given: 

n =1,245 joules

T= 400 degrees Kelvin 

V= 2.5 liters

R= constant

P=?

 

 

P=nRT/V

P= (1,245 J)(0.082057 Latm/Kmol)(400K)

                  2.5 liters

 = 40864.386

        2.5

= 16345.7544

 

Answer 2

Answer: The pressure of gas will be 1328 Joules

Step-by-step explanation:

Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.

The combined gas equation is,

$\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}$   (for same value of n)

where,

$P_1$ = initial pressure of gas = 1245 J

$P_2$ = final pressure of gas = ?

$V_1$ = initial volume of gas = 2 L

$V_2$ = final volume of gas = 2.5L

$T_1$ = initial temperature of gas = 300K

$T_2$ = final temperature of gas = 400K

Now put all the given values in the above equation, we get the final pressure of gas.

$\frac{1245\times 2}{300K}=\frac{P_2\times 2.5}{400}$

$P_2=1328J$

Therefore, the final pressure of gas will be 1328 Joules.