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Question
How will you prove experimentally that different substances have different specific heat capacities?
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Solution
Experiment to prove different substances have different specific heat capacities:
- Take three balls of iron, copper, and lead of equal mass and put them in boiling water for some time. Then, take them out of the water and measure their temperature.
- All of them will be at temperature 100oC. Now, put them immediately on the thick slab of wax. Note the depth that each of the balls goes into the wax. The ball which absorbs more heat from the water will give more heat to wax. More wax will thus melt and the ball will go deeper into the wax. It will be observed that the iron ball goes deepest into the wax. The lead ball goes the least and the copper ball goes to intermediate depth. This shows that for the equal rise in temperature, the three balls have absorbed different amounts of heat.
- This means that the property which determines the amount of heat absorbed by a ball is different for the three balls. This property is called the specific heat capacity.
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Molar specific heat (Cv) (cal mol–1 K–1) |
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| Nitrogen | 4.97 |
| Oxygen | 5.02 |
| Nitric oxide | 4.99 |
| Carbon monoxide | 5.01 |
| Chlorine | 6.17 |
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