Q.Explain how heat absorbed at constant volume is measured using bomb calorimeter with a neat diagram.

Step 1. The bomb calorimeter's inner vessel (the 'bomb') and its cover are made of strong steel, sealed tightly with a metal lid and screws -- so its internal volume cannot change during the reaction (Figure 7.6).

Step 2. A weighed amount of the combustible substance sits in a small platinum cup, wired to electrical ignition leads; the bomb is closed and pressurised with excess oxygen, then immersed in water inside the calorimeter, with a stirrer keeping the water uniformly mixed.

Step 3. Striking the sample electrically ignites combustion; the heat evolved is absorbed by both the calorimeter itself and the surrounding water, and the resulting temperature rise is measured with a sensitive Beckman thermometer. …

Walk through the apparatus (Figure 7.6) piece by piece, then explain WHY its sealed, fixed volume makes t …

• Describing the apparatus without explaining WHY the sealed bomb gives $\Delta U$ (not $\Delta H$) -- the constant-volume reasoning is the ac …