Calculate the pressure in a 3.00L sealed container where 20.0g of nitrogen gas, N2 is added to this container at 31.0°C.

Step 1:
First, we need to calculate the number of moles of nitrogen gas using the ideal gas law formula:

PV = nRT where:
- P is the pressure (in atm),
- V is the volume (in L),
- n is the number of moles,
- R is the ideal gas constant (0.0821 L.atm/mol.K),
- T is the temperature (in Kelvin).

Given:
V = 3.00L ,
m = 20.0g ,
Molarmass(M_w)\approx28.01g/mol ,
T = 31.0°C = 31 + 273.15 = 304.15K

Calculate moles of N_2 :

\text{moles}=\dfrac{m}{M_w}=\dfrac{20.0g}{28.01g/mol}\approx0.714\text{ mol}

Step 2:
Now, substitute the values into the ideal gas law formula to find the pressure:

PV = nRT

P\times3.00L=0.714mol\times0.0821\dfrac{L.atm}{mol.K}\times304.15K

P=\dfrac{0.714mol\times0.0821\dfrac{L.atm}{mol.K}\times304.15K}{3.00L}

Step 3:
Solve for the pressure P :

P=\dfrac{0.714\times0.0821\times304.15}{3.00}

P\approx5.94\text{ atm}

\textbf{Answer:} The pressure in the sealed container is 5.94\text{ atm}