Physics
Calculate the mass of ice needed to cool 150 g of water contained in a calorimeter of mass 50 g at 32°C such that the final temperature is 5°C.
Specific heat capacity of calorimeter = 0.4 J g-1 °C-1
Specific heat capacity of water = 4.2 Jg-1°C-1
Latent heat capacity of ice = 330 Jg-1
Calorimetry
ICSE 2017
52 Likes
Answer
Given,
Mass of water m1 = 150 g
Mass of calorimeter m2 = 50 g
Temperature of water t1 = 32°C
Final temperature t = 5°C
Let m be the mass of ice added
Heat given by calorimeter Q1 = m2 c2 x (t1 - t)
= 50 x 0.4 x (32 - 5) = 540 J
Heat given by water Q2 = m1 c1 x (t1 - t)
= 150 x 4.2 x (32 - 5) = 17010 J
Heat taken by ice to melt at 0°C = m L
= m x 330 Jg-1
Heat energy taken by the melted ice to to raise it's temperature from 0°C to 5 °C
= m x 4.2 x (5 - 0) = 21m J
Total heat taken by ice = 330m + 21m = 351 m J
By principle of calorimeter, if there is no loss of heat.
351 m = 540 + 17010
m = = 50 g
Answered By
17 Likes
Related Questions
A pulley system with V.R. = 4 is used to lift a load of 175 kgf through a vertical height of 15 m. The effort required is 50 kgf in the downward direction. (g = 10 N kg-1)
Calculate:
(i) Distance moved by the effort.
(ii) Work done by the effort.
(iii) M.A. of the pulley system.
(iv) Efficiency of the pulley system.
(i) How is the transference of heat energy by radiation prevented in a calorimeter?
(ii) You have a choice of three metals A, B and C, of specific heat capacities 900 Jkg-1°C-1, 380 Jkg-1°C-1 and 460 Jkg-1°C-1 respectively, to make a calorimeter. Which material will you select? Justify your answer.
(i) Name the radiations which are absorbed by greenhouse gases in the earth’s atmosphere.
(ii) A radiation X is focused by a particular device on the bulb of a thermometer and mercury in the thermometer shows a rapid increase. Name the radiation X.
(iii) Name two factors on which the heat energy liberated by a body depends.
A lens forms an upright and diminished image of an object when the object is placed at the focal point of the given lens.
(i) Name the lens.
(ii) Draw a ray diagram to show the image formation.