Question

Dry ice is solid carbon dioxide. A 1.65−g sample of dry ice is placed in an evacuated 3.93−L vessel at 23.0°C. Calculate the pressure inside the vessel after all the dry ice has been converted to CO2 gas.

Answer 1

Answer: The pressure of the gas inside the vessel is 0.232 atm

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass of carbon dioxide = 1.65 g

Molar mass of carbon dioxide = 44 g/mol

Putting values in above equation, we get:

$\text{Moles of carbon dioxide}=\frac{1.65g}{44g/mol}=0.0375mol$

To calculate the pressure of the gas, we use the equation given by ideal gas which follows:

PV=nRT

where,

P = pressure of the gas = ?

V = Volume of the gas = 3.93 L

T = Temperature of the gas = $23^oC=[23+273]=296K$

R = Gas constant = $0.0821\text{ L. atm }mol^{-1}K^{-1}$

n = number of moles of gas = 0.0375 moles

Putting values in above equation, we get:

$P\times 3.93L=0.0375mol\times 0.0821\text{ L. atm }mol^{-1}K^{-1}\times 296K\\\\P=\frac{0.0375\times 0.0821\times 296}{3.93}=0.232atm$

Hence, the pressure of the gas inside the vessel is 0.232 atm