For the reaction of one mole of zinc dust with one mole of sulphuric acid in a bomb calorimeter `DeltaU`and`w` correspond to

Options

A. `Delta U lt 0, w = 0`
B. `Delta U lt 0, w lt 0`
C. `Delta U gt 0, w = 0`
D. `Delta U gt 0, w gt 0`

Answer

A

Explanation

A bomb calorimeter is a closed vessel, i.e., `Delta V = 0`. Thus, no pressuer-volume work is possible when a reaction is carried out in a bomb calorimeter, i.e., `W = p Delta V = 0`. Accoding to the first law of thermodynamics.
`Delta U = q + w`
As `w = 0`, we have
`Delta U = q`
Since the reaction between `Zn` and `H_(2) SO_(4)` is an exothermic reaction (it is a redox reaction), `q` is negative. Hence, `Delta U` is also negative `(lt 0)`.