Advertisements
Advertisements
प्रश्न
A vessel of negligible heat*capacity contains 40g of ice in it at 0°C, 8g of steam at 100°C is passed into the ice to melt it. Find the final temperature of the contents of the vessel.
(Specific latent heat of vaporization of steam = 2268 J/g, specific latent heat of fusion of ice = 336 J/f and specific heat capacity of water = 4.2 J/g°C)
उत्तर
Assume, final temperature of contents = θ°C. Heat gained by ice at 0°C to water at 0°C + heat gained by water at 0°C to water at 0°C = Heat lost by steam at 100°C + Heat lost by water at 100°C to water at 0°C.
mLf + mcΔθ = mL + mcΔθ
40 × 336 + 40 × 4.2 × (θ - 0) = 8 × 2268 + 8 × 4.2 × (100 - θ)
13440 + 168 θ = 18144 + 3360 - 33.6 θ
168 θ + 33.60 = 8064 θ
201.6 θ = 8064 θ = 40°C
APPEARS IN
संबंधित प्रश्न
A child running a temperature of 101°F is given an antipyrin (i.e. a medicine that lowers fever) which causes an increase in the rate of evaporation of sweat from his body. If the fever is brought down to 98 °F in 20 min, what is the average rate of extra evaporation caused, by the drug? Assume the evaporation mechanism to be the only way by which heat is lost. The mass of the child is 30 kg. The specific heat of human body is approximately the same as that of water, and latent heat of evaporation of water at that temperature is about 580 cal g–1.
Ice cream appears colder to the mouth than water at 0℃. Give reason.
Solve the following problems:
Equal heat is given to two objects A and B of mass 1 g. Temperature of A increases by 3°C and B by 5°C. Which object has more specific heat? And by what factor?
Why are athletes advised to put on extra clothes after competing on event?
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?
Define specific heat capacity.
Explain why the specific heat capacity at constant pressure is greater than the specific heat capacity at constant volume.
At same temperature and pressure of an ideal gas, ____________.
Match the following
| 1. | Specific heat capacity | a. | Dewar bottle |
| 2. | Calorimeter | b. | Lavoisier and Simon |
| 3. | Vacuum flask | c. | J Kg-1 K-1 |
| 4. | Ice – calorimeter | d. | Heat capacity |
