10 m3 of carbon dioxide is originally at a temperature of 50 °C and pressure of 10 kPa. Determine the new density and volume of the carbon dioxide if the temperature and pressure change to 75 oC and 15 kPa.

Respuesta :

Answer : The new density and new volume of carbon dioxide gas is 0.2281 g/L and [tex]7.2m^3[/tex] respectively.

Explanation :

First we have to calculate the new or final volume of carbon dioxide gas.

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

The combined gas equation is,

[tex]\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}[/tex]

where,

[tex]P_1[/tex] = initial pressure of gas = 10 kPa

[tex]P_2[/tex] = final pressure of gas = 15 kPa

[tex]V_1[/tex] = initial volume of gas = [tex]10m^3[/tex]

[tex]V_2[/tex] = final volume of gas = ?

[tex]T_1[/tex] = initial temperature of gas = [tex]50^oC=273+50=323K[/tex]

[tex]T_2[/tex] = final temperature of gas = [tex]75^oC=273+75=348K[/tex]

Now put all the given values in the above equation, we get:

[tex]\frac{10kPa\times 10m^3}{323K}=\frac{15kPa\times V_2}{348K}[/tex]

[tex]V_2=7.2m^3[/tex]

The new volume of carbon dioxide gas is [tex]7.2m^3[/tex]

Now we have to calculate the new density of carbon dioxide gas.

[tex]PV=nRT\\\\PV=\frac{m}{M}RT\\\\P=\frac{m}{V}\frac{RT}{M}\\\\P=\rho \frac{RT}{M}\\\\\rho=\frac{PM}{RT}[/tex]

Formula for new density will be:

[tex]\rho_2=\frac{P_2M}{RT_2}[/tex]

where,

[tex]P_2[/tex] = new pressure of gas = 15 kPa

[tex]T_2[/tex] = new temperature of gas = [tex]75^oC=273+75=348K[/tex]

M = molar mass of carbon dioxide gas = 44 g/mole

R = gas constant = 8.314 L.kPa/mol.K

[tex]\rho[/tex] = new density

Now put all the given values in the above equation, we get:

[tex]\rho_2=\frac{(15kPa)\times (44g/mole)}{(8.314L.kPa/mol.K)\times (348K)}[/tex]

[tex]\rho_2=0.2281g/L[/tex]

The new density of carbon dioxide gas is 0.2281 g/L