Respuesta :
Answer : The total pressure in the flask is 1.86 atm.
Explanation :
First we have to calculate the pressure of [tex]CO_2[/tex] gas.
Using ideal gas equation :
[tex]PV=nRT\\\\P_{CO_2}=\frac{w}{M}\frac{RT}{V}[/tex]
where,
P = Pressure of [tex]CO_2[/tex] gas = ?
V = Volume of [tex]CO_2[/tex] gas = 765 mL = 0.765 L (1 L = 1000 mL)
n = number of moles
w = mass of [tex]CO_2[/tex] gas = 1.25 g
M = molar mass of [tex]CO_2[/tex] gas = 44 g/mol
R = Gas constant = [tex]0.0821L.atm/mol.K[/tex]
T = Temperature of [tex]CO_2[/tex] gas = [tex]25.0^oC=273+25.0=298K[/tex]
Putting values in above equation, we get:
[tex]P_{CO_2}=\frac{w}{M}\frac{RT}{V}[/tex]
[tex]P_{CO_2}=\frac{1.25g}{44g/mol}\frac{(0.0821L.atm/mol.K)\times 298K}{0.765L}=0.909atm[/tex]
Now we have to calculate the total pressure in the flask.
[tex]P_T=P_{N_2}+P_{CO_2}[/tex]
Given :
[tex]P_{CO_2}=0.909atm[/tex]
[tex]P_{N_2}=725mmHg=\frac{725}{760}=0.954atm[/tex]
conversion used : (1 atm = 760 mmHg)
Now put all the given values in the above expression, we get:
[tex]P_T=0.954atm+0.909atm=1.86atm[/tex]
Therefore, the total pressure in the flask is 1.86 atm.
