The hydrocarbon naphthalene calculations

The hydrocarbon naphthalene was frequently used in mothballs until recently, when it was discovered that human inhalation of naphthalene vapors can lead to haemolytic anemia. Naphthalene is 93.71% carbon by mass, and a 0.260-mole sample of naphthalene has a mass of 33.3 g. What is the molecular formula of naphthalene? (Naphthalene only contains carbon and hydrogen.)
its C10H8

This compound works as a pesticide in mothballs by sublimation of the solid so that it fumigates enclosed spaces with its vapors according to the following equation.naphthalene(s) naphthalene(g) K = 4.29 ✕ 10−6 (at 298 K)

If 2.85 g of solid naphthalene is placed in an enclosed space with a volume of 5.15 L at 25°C, what percentage of the naphthalene will have sublimed once equilibrium has been established?

Naphthalene (s) Naphthalene(g) ; K = 4.29 x 10^-6

Molar mass of naphthalene = 128 g/mol

Initial number of moles of naphthalene = 2.85 g /128 g/mol

                           = 0.0223 mol

Let x moles of Naphthalene is sublimed and develop an ICE table 

      Naphthalene (s) Naphthalene (g)

I      0.0223 mol                          0

C          -x                                    x

E       0.0223-x                            x

K = [ Naphthalene (g)] / [Naphthalene (s)]

4.29 x 10^-6 = x / 0.0223-x

by solving , x = 9.6 x 10^-8 mol

hence ,percent of naphthalene sublimed at the equilibrium

           = (9.6 x 10-8 mol / 0.0223mol)*100

                       = 4.3 x 10^-4%

>>Having difficult problems and need solutions in few minutes ?Contact us at<<

Was this helpful,would like to support us?

<<click here to support us>>

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s