Advertisements
Advertisements
Question
1 kg of molten lead at its melting point of 327°C is dropped into 1 kg of water at 20°C. Assuming no loss of heat, calculate the final temp. of water. (Sp. heat of lead = 130 J/kg°C, latent heat of lead = 27000 J/kg and Sp. heat of water = 4200 J/kg°C).
Solution
Let the final temperature of the mixture be t
Heat lost by lead = Heat gained by water
m1L + m1 x CL x (327 - t) = mz x cw x (t - 20)
1 x 27000 + 1 x 130 x (327 - t) = 1 x 4200 x (t - 20)
27000 + 42510 _ 130t = 4200t - 84000
t = 35.45°C
So, the final temperature of water is 35.45°C.
APPEARS IN
RELATED QUESTIONS
Differentiate between heat and temperature.
The temperature of 600 g of cold water rises by 15° C when 300 g of hot water at 50° C is added to it. What was the initial temperature of the cold water?
The melting point of naphthalene is 80°C and the room temperature is 30°C. A sample of liquid naphthalene at 100°C is cooled down to the room temperature. Draw a temperature time graph to represent this cooling. In the graph, mark the region which corresponds to the freezing process.
How much steam at 100oC must be passed into 120 g of water at 20oC to raise the temperature to 40oC?
100 g of ice at -10°C is heated. It is converted into steam. Calculate the quantity of heat which it has consumed. (Sp. heat of ice = 2100J/kg°C, sp. heat of water= 4200 J/kgK, sp. heat of water = 42000 J/kgK, sp. latent heat of ice = 2260000 J/kg).
What mass of ice at 0°C will be required to cool 0.9 kg of water from 35°C to 0°C? Assume all the ice used melts. The specific heat capacity of water is 4.2 x 103 J/kgoC and specific latent heat of fusion of ice is 336 x 103 J/kg.
Name the material of which it is made of. Give two reasons for using the material stated by you.
40g of ice at 0°C is used to bring down the temperature of a certain mass of water at 60°C to 10°C. Find the mass of water used.
[Specific heat capacity of water = 4200 J kg-1 °C-1]
[Specific latent heat of fusion of ice = 336 × 103 J kg-1]
50 g of ice at 0°C is added to 300 g of a liquid at 30°C. What will be the final temperature of the mixture when all the ice has melted? The specific heat capacity of the liquid is 2.65 Jg-1 °C-1 while that of water is 4.2 J g-1 °C-1. Specific latent heat of fusion of ice = 336 Jg-1.
Write one characteristic property of the material chosen for making a calorimeter.
