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प्रश्न
Decide the unit for specific heat capacity.
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उत्तर
- The amount of heat (Q) required to change the temperature of a substance is directly proportional to:
a. the mass of the substance (m).
b. change in temperature of the substance (ΔT).
∴ Q ∝ m and Q ∝ ΔT
∴ Q ∝ mΔT
∴ Q = cmΔT ....(1)
where ‘c’ is specific heat or specific heat capacity of a substance. From equation (1),
c = `"Q"/("m" Delta "T")` ....(2) - SI unit:
As SI unit of heat is J, mass is kg and change in temperature is °C, SI unit of specific heat capacity is J/kg °C - C.G.S. unit:
As CGS unit of heat is calorie, mass is g and change in temperature is °C, CGS unit of specific heat capacity is cal/g °C
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संबंधित प्रश्न
Given below are observations on molar specific heats at room temperature of some common gases.
| Gas |
Molar specific heat (Cv) (cal mol–1 K–1) |
| Hydrogen | 4.87 |
| Nitrogen | 4.97 |
| Oxygen | 5.02 |
| Nitric oxide | 4.99 |
| Carbon monoxide | 5.01 |
| Chlorine | 6.17 |
The measured molar specific heats of these gases are markedly different from those for monatomic gases. Typically, molar specific heat of a monatomic gas is 2.92 cal/mol K. Explain this difference. What can you infer from the somewhat larger (than the rest) value for chlorine?
What do you understand by the following statements:
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