Advertisements
Advertisements
प्रश्न
Write a short note.
Specific heat capacity
Advertisements
उत्तर
- The amount of heat energy required to raise the temperature of a unit mass of an object by 1 °C is called the specific heat or specific heat capacity of that object.
- SI unit of specific heat capacity is J/kg °C and CGS unit is cal/g °C
- It is denoted by ‘c’ and given by formula: c = `"Q"/("m"Delta "T")`
- Specific heat is a property of a substance and is different for different substances.
- Higher the value of specific heat capacity of the substance, higher is the amount of heat energy required to raise its temperature by 1 °C.
- The specific heat capacity of object is measured using principle of heat exchange.
संबंधित प्रश्न
In an experiment on the specific heat of a metal, a 0.20 kg block of the metal at 150 °C is dropped in a copper calorimeter (of water equivalent 0.025 kg) containing 150 cm3 of water at 27 °C. The final temperature is 40 °C. Compute the specific heat of the metal. If heat losses to the surroundings are not negligible, is your answer greater or smaller than the actual value for the specific heat of the metal?
Describe a method to determine the specific heat capacity of a solid, like a piece of copper ?
A heater of power P watt raises the temperature of m kg of a liquid by Δt K in time t s. Express
the specific heat capacity of liquid in terms of above data.
Find the time taken by a 500 W heater to raise the temperature of 50 kg of material of specific heat capacity 960 J kg-1K-1, from 18°C to 38° C. Assume that all the heat energy supplied by the heater is given to the material.
How much heat energy is released when 5.0 g of water at 20℃ changes into ice at 0℃? Take specific heat capacity of water = 4.2 J g-1 K-1, Specific latent heat of fusion of ice = 336 J g-1.
State three ways to minimize the global warming.
Name and state the principle used to measure the specific heat capacity of a substance.
What is the specific heat capacity of melting ice?
State, with reason, which of the two, boiling water or steam both at 100°C will produce more severe burns.
Fill in the following blank using suitable word:
SI unit of heat is .........
Water boils at 120 °C in a pressure cooker. Explain the reason.
Write two advantages of high specific heat capacity of water.
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.
Solve the following problem.
Specific latent heat of vaporization of water is 2.26 × 106 J/kg. Calculate the energy needed to change 5.0 g of water into steam at 100 ºC.
Read this activity and answer the following questions.
- Take three spheres of iron, copper and lead. the lead of equal mass.
- Put all the three spheres in boiling water in the beaker for some time.
- Take the three spheres out of the water.
- All the spheres will be at a temperature 100 °C.
- Put them immediately on the thick slab of wax.
- Note, the depth that each of the sphere goes into the wax.
Questions:
- Which property is determined from this activity?
- Give name to that property.
- Explain the term principal of heat exchange with the help of this activity.
The heat capacity of the vessel of mass 100 kg is 8000 J/°K. Find its specific heat capacity.
Numerical Problem.
How much heat energy is required to change 2 kg of ice at 0°C into water at 20°C? (Specific latent heat of fusion of water = 3,34,000 J/kg, Specific heat capacity of water = 4200 JKg–1K–1).
The molar specific heats of an ideal gas at constant pressure and constant volume are denoted by Cp and Cv respectively. If `gamma = "C"_"p"/"C"_"v"` and R is the universal gas constant, then Cp is equal to ______.
The ratio of the specific heats `c_"p"/c_"v"=gamma` in terms of degrees of freedom 'n' is given by ______.
Two metals A and B have specific heat capacities in the ratio 2:3. If they are supplied same amount of heat then
Which metal piece will have greater mass if the rise in temperature is the same for both metals?
