Question

Sulfur hexafluoride, a dense gas, is held in two separate containers in a storage room at an atmospheric pressure of 755 mmHg and 20.3 °C. The volume of container 1 is 2.09 L, and it contains 7.61 mol of the gas. The volume of container 2 is 4.46 L. Determine the moles of F atoms in container 2 and the density of the gas at the conditions in the room

Answer 1

Explanation:

As it is given that both the given containers are at same temperature and pressure, therefore they have the same density.

So, mass of $SF_{6}$ in container- 1 is as follows.

    5.35 mol x molar mass of $SF_{6}$

            = 7.61 mol x 146.06 g/mol

             = 1111.52 g

Therefore, density of $SF_{6}$ will be calculated as follows.

            Density = $\frac{mass}{volume}$  

         density = $\frac{1111.52 g}{2.09 L \times 1000 ml/L}$

                       = 0.532 g/mL

Now, mass of $SF_{6}$ in container- 2 is calculated as follows.

        4.46 L x 1000 mL/L x 0.532 g/mL

            = 2372.72 g

Hence, calculate the moles of moles $SF_{6}$ present in container 2 as follows.

  No. of moles = $\frac{mass}{\text{molar mass}}$  

                        = $\frac{2372.72 g}{146.06 g/mol}$

                        = 16.24 mol

Since, 1 mol $SF_{6}$ contains 6 moles F atoms .

So, 16.24 mol  $SF_{6}$ contains following number of atoms.

                = $16.24 mol \times 6$

                = 97.46 mol

Thus, we can conclude that moles of F atoms in container 2 are 97.46 mol.