If 4.05 g of kno₃ reacts with sufficient sulfur (s₈) and carbon (c), how much p-v work will the gases do against an external pressure of 1.00 atm given the densities of nitrogen and carbon dioxide are 1.165 g/l and 1.830 g/l, respectively, at 20°c?

Explanation:

Chemical reaction equation for the given reaction is as follows.

Therefore, we will calculate the number of moles of as follows.

    No. of moles =

                          =

                          = 0.04 mol

Number of moles of nitrogen gas formed is calculated as follows.

    No. of moles =

                          =

                          = 0.02 mol

Mass of gas formed will be calculated as follows.

               No. of moles × Molar mass of

              =

              = 0.56 g

Now, the number of moles of formed is as follows.

              =

              = 0.06 mol

Hence, mass of formed will be as follows.

               = 1.76 g

Volume  of is calculated as follows.

               Volume =

                             =

                             = 0.48 L

And, volume of is calculated as follows.

                 Volume =

                             =

                             = 0.96 L

Let us assume that the volume of solids are negligible. Therefore, total volume will be as follows.

            = (0.48 L + 0.96 L)

                           = 1.44 L

Relation between work, pressure and volume is as follows.

          w = -

              = -

              = -1.44 atm L

As 1 tm L = 101.3 J. So, convert 1.44 atm L into joules as follows.

               = 145.87 J

Thus, we can conclude that the given gases will do 145.87 J of work.