130 g of Zn is dissolved in dilute sulphuric acid in an open beaker . Find the work done in the process assuming isothermal operation.

Options

A. `-1200` cal
B. `-1800` cal
C. `+1800` cal
D. none

Answer

A

Explanation

Beaker is open and in open beaker external pressure remains constant
`2n+ H_(2)SO_(4) to ZnSO_(4) + H_(2)(g)`
`130/65 = 2` mol
Pv = nRT
`PDeltaV = Deltan_(g)RT`
`W =-Deltan_(g)RT = -2 xx 2 xx 300 = -1200` cal