Question

For the reaction of one mole of zinc dust with one mole of sulphuric acid in a bomb calorimeter, $\Delta U$ and W correspond to

• A. $\Delta U<0,W=0$
• B. $\Delta U<0,W<0$
• C. $\Delta U<0,W=0$
• D. $\Delta U<0,W>0$

Answer 1

The correct option is A

$\Delta U<0,W=0$

Bomb calorimeter is commonly used to find the heat of combustion of organic substances which consists of a sealed combustion chamber, called a bomb. If a process is run in a sealed container then no expansion or compression is allowed, so $W=0$ and $\Delta U=q$.
The given reaction is exothermic so some heat will be evolved which will result in lowering of internal energy.
$\therefore \Delta U<0,W=0$

Hence, option (a) is correct.