Advertisements
Advertisements
प्रश्न
The ratio of specific heat capacity to molar heat capacity of a body _____________ .
विकल्प
is a universal constant
depends on the mass of the body
depends of the molecular weight of the body
is dimensionless
उत्तर
depends of the molecular weight of the body
Specific heat capacity of a body,
\[s = \frac{Q}{m\Delta\theta}\]
Here,
Q = Heat supplied
m = Mass of body
Δθ = Change in temperature
Molar heat capacity of a body,
\[C = \frac{Q}{n\Delta\theta}\]
Here,
Q = Heat supplied
n = Number of moles
Δθ = Change in temperature
∴ The ratio of the specific heat capacity and molar heat capacity is given by
\[\frac{s}{C} = \frac{\frac{Q}{m\Delta\theta}}{\frac{Q}{n\Delta\theta}} = \frac{n}{m} = \frac{n}{nM} = \frac{1}{M}\]
Here,
M = Molar mass related to number of moles
m = Mass
As the value of M is different for different bodies of different composition, the ratio cannot be a universal constant.
Also, the ratio is independent of the mass of the body.
The ratio of the specific heat and molar heat capacity depends on the molecular weight of the body.
Clearly, the unit of molecular weight is kg/mole. So, the ratio that depends only on the molecular weight cannot be dimensionless.
APPEARS IN
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?
A geyser heats water flowing at the rate of 3.0 litres per minute from 27 °C to 77 °C. If the geyser operates on a gas burner, what is the rate of consumption of the fuel if its heat of combustion is 4.0 × 104 J/g?
The coolant in a chemical or a nuclear plant (i.e., the liquid used to prevent the different parts of a plant from getting too hot) should have high specific heat.
Define heat capacity and state its SI unit.
A solid of mass 50 g at 150 °C is placed in 100 g of water at 11 °C when the final temperature recorded is 20 °C. Find the specific heat capacity of the solid. (specific heat capacity of water = 4.2 J/g °C)
50 g of metal piece at 27°C requires 2400 J of heat energy so as to attain a temperature of 327°C . Calculate the specific heat capacity of the metal.
Heat energy is supplied at a constant rate to 100g of ice at 0 °C. The ice is converted into water at 0° C in 2 minutes. How much time will be required to raise the temperature of water from 0 °C to 20 °C? [Given: sp. heat capacity of water = 4.2 J g-1 °C-1, sp. latent heat of ice = 336 J g-1].
Give a mathematical relation between Heat Capacity and Specific Heat Capacity.
Differentiate between heat capacity and specific heat capacity.
A mass m1 of a substance of specific heat capacity c1 at temperature t1 is mixed with a mass m2 of other substance of specific heat capacity c2 at a lower temperature t2. Deduce the expression for the temperature t of the mixture. State the assumption made, if any.
The S.I. unit of specific heat capacity is ______.
Why do bottled soft drinks get cooled, more quickly by the ice cubes than by the iced water, both at 0℃?
It is generally cold after a hail-storm then during and before the hail storm. Give reason.
How will rise in sea level affect population in coastal countries?
How will climate changes affect the various animal species?
How will global warming disturb the ecological balance?
State three ways to minimize the global warming.
Study the following procedure and answer the questions below:
1. Take 3 spheres of iron, copper and lead of equal mass.
2. Put all the 3 spheres in boiling water in a beaker for some time.
3. Take 3 spheres out of the water. Put them immediately on a thick slab of wax.
4. Note, the depth that each sphere goes into the wax.
i) Which property of substance can be studied with this procedure?
ii) Describe that property in minimum words.
iii) Explain the rule of heat exchange with this property.
The specific heat capacity of a body depends on _____________ .
650 J of heat is required to raise the temp. of 0.25 kg of lead from 15°C to 35°C. Calculate the Sp. heat capacity of lead.
m kg of a substance of specific heat capacity s J/kg °C is heated so that its temperature rises from θ1°C to θ2°C. Write down the expression for the heat Q supplied.
Write the approximate values of the specific latent heat of fusion of ice.
Why is specific heat capacity taken as a measure of thermal inertia?
Some heat is provided to a body to raise its temperature by 25°C. What will be the corresponding rise in temperature of the body as shown on the Kelvin scale?
If, in a central heating system, steam enters a radiation pipe at 100°C and water leaves the radiation pipe at 100°C, can this radiation pipe heat a room? Give an explanation for your answer.
Ice-cream at 0°C feels colder than water at 0°C. Give reason for this observation.
Discuss how high specific heat capacity of water helps in formation of land and sea breeze.
A. hot solid of mass 60 g at 100°C is placed in 150 g of water at 20° C. The final steady temperature recorded is 25°C. Calculate the specific heat capacity of the solid. [Specific heat capacity of water = 4200 J kg-1 °C-1]
Answer the following question.
Why do we generally consider two specific heats of a gas?
The cold object the hot object enclosed in one box of heat-resistant material.
- What changes will occur in the two objects when temperature flows from those objects?
- Which principle can show that the energy exchange takes place between two objects only when kept in isolated system?
For a gas `"R"/"C"_"v" = 0.4,` where 'R' is the universal gas constant and 'Cv' is molar specific heat at constant volume. The gas is made up of molecules which are ______.
If 'f' is the number of degrees of freedom of a molecule of a gas and ratio of molar specific heats of a gas, ϒ = 1 + `2/"f"` where ϒ = Cp/Cv. The ratio of 'ϒ' for monoatomic gas to 'ϒ' for (rigid) f diatomic gas is ______.
On supplying 100 µC of charge to a conductor, its potential rises by 5 V then capacity of the conductor is ______.
Two metals A and B have specific heat capacities in the ratio 2 : 3. If they are supplied the same amount of heat then
Which metal piece will show a greater rise in temperature given their masses is the same?
Specific heat capacity C = ______.
Water has the lowest specific heat capacity.
