Calorimetry Questions and Answers

Hence temperature of mixture will remain at 100 C llustration 14 A calorimeter of heat capacity 100 J K is at room temperature of 30 C 100 g of water at 40 C of spe heat 4200 J kg K is poured into the calorimeter What is the temperature of water in calorimeter

33 One end of a glass capillary tube with a radius r 0 05 cm is immersed into water to a depth of h 2 cm What pressure is required to blow an air bubble out of the lower end of the tube T 7x 10 2 N m and p 103 kg m a 480 N m c 120 N m b 680 N m d 820 N m

5 1 kg of ice at 0 C 1 kg water at 100 C and 1 kg steam at 100 C are mixed in an insulated closed container After equilibrium is established the amount of ice water and steam are m m and m kg respectively Which of the following options is correct L 80 cal gm L 540 cal gm S 1 m kg m 1 kg m kg 2 m 0 5 kg m 2 kg m 0 5 kg 2 3 3 m 0 kg m 1kg m kg m kg

Steel and copper wires of same length are stretched by the same weight one after the other Young s modulus of steel and copper are 2 10 N m and 1 2 x 10 N m The ratio of increase in length O 2 5 3 5

The mass of ice that can transistion to being a liquid by being melted by 1 gram of 100 C steam is Hint Don t forget about hot water remaining from condensed steam c 1 cal gram Lf 80 cal g Lv 540 cal g A 6 75 grams B 0 148 gram C 0 125 gram D 8 grams E none of the above

Suppose that you tercept 5 0 10 3 of the energy radiated by a hot sphere that has a radius of 0 020 m an emissivity of 0 80 and a surface temperature of 500 K How much energy do you intercept in 2 0 min 10 5 J 50 J 0 0725 J 8 55 J

vapor at a temperature of 200 F b You have 200 g of coffee at 45 C Coffee has the same specific heat as water How much 5 C ice do you need to add to reduce the coffee s temperature to 30 C

In two experiments with a continuous flow calorimeter to determine the specific heat capacity of a liquid an input power of 60 W produced a rise of 10 K in the liquid When the power was doubled the same temperature rise was achieved by making the rate of flow of liquid three times faster The power lost to the surroundings in each case was A 20 W B 30 W Window A is a pane of glass 4 millimetr C 40 W D 120 W

Steam at 100 C is passed into 2 0 kg of water contained in a calorimeter of water equivalent 0 02 kg at 15 C till the temperature of the calorimeter and its contents rises to 95 C The mass of steam condensed in kg is 1 0 301 2 0 298 4 2 02 3 0 60

The temperature of 40 gram of water at 20 C would be raised most when mixed with Assume specific heat of water is 1 cal g C 40 g water at 30 C 20 g water at 40 C 50 g water at 10 C 10 g water at 70 C

The rms speed of molecules of hydrogen at 27 C is v Then the temperature at which the rms speed of hydrogen molecules will be 2v is 150 K 600 K 1200 K 279 K

3 57 2 You take an ice cream out of the freezer ketp at 18 C outside it is 32 C After one minute the ice creeam has warmed to 8 C what is the temperature of the icecream ofter five minutes Ans 15 6 C

If 150 gram ice at 0 C is mixed with 10 gram steam at 100 C then final temperature of composition under ideal condition is 1 Less than 0 C 3 10 C 2 0 C 4 28 C

2 A thermally insulated vessel contains 150 g of water at 0 C Then the air from the vessel is pumped out adiabatically A fraction of water turns into ice and the rest evaporates at 0 C itself The mass of evaporated water will be closest to Latent heat of vaporisation of water 210x 106 Jkg and latent heat of fusion of water 3 36 105 Jkg a 150 g 1 20 g c 130 g 2019 Main 8 April I d 35g

The melting point of a substance X is 25 C Liquid X at 40 C is slowly added to 20 g of solid X at 20 C kept in an insulated container It is found that solid X begins to melt after the addition of 8 g of liquid X and the solid X has melted completely after the addition of 88 g of liquid X If C and C denote the specific heat of solid and liquid X respectively and the latent heat of fusion of solid X is 150 kJ kg which of these options is are correct 0 M O C5 3 0 kJ kg C CL 2 5 kJ kg C Cs 3 6 kJ kg C C 3 0 kJ kg C

Heat required to change 20 g ice at 20 C into steam at 100 C is Specific heat of ice 0 5 and of water 1 cal g C cal latent heat of vaporization of water 540 latent g cal g C 2400 cal heat of fusion of ice 80 13000 cal 14600 cal 80 cal

10 A pressure cooker having ice at 20 C is heated at constant heat supply rate till the steam comes out at 350 C The possible graphical variation of temperature T of cooker with time t is best shown by Assume ideal situation TA 1 3 TA t 2 4 TA TA V t t

NEET 24 M kilogram of ice is being heated from T C to T C and variation of its temperature T along with heat inputs Q is shown Latent heat of melting process can be calculated as T Temperature T O T 1 Q M Q Q Q 2 Q Heat input Q Q M Q3 Q 2

D A body at temperature T is getting cooled in an atmosphere of temperature To Assuming Newton s law of cooling to be valid which of the following graphs shows the vartiation of In T To with time 1 3 In T T In T T 2 4 In T T In T T

Example 16 12 In a container of negligible mass 30 g of steam at 100 C is added to 200 g of water that has a temperature of 40 C If no heat is lost to the surroundings what is the final temperature of the system Also find masses of water and steam in equilibrium Take Ly 539 cal g and 1

18 Steam is passed into 54 gm of water at 30 C till th temperature of mixture becomes 90 C If the latent he of steam is 536 cal gm the mass of the mixture will be

Illustration 4 An air bubble doubles in radius on rising from bottom of a lake to its surface If the atmosphere pressure is equal to that due to a column of 10 m of water then the depth of the lake is Ignore surface tension

42 1 g of a steam at 100 C melt how much ice at 0 Latent heat of ice 80 cal gm and latent heat of stea 540 cal gm a 1 gm c 4 gm b 2 gm d 8 gm

Illustration 7 A mixture containing hydrogen and oxygen is having a volume 2000 cm temperature 300 K and pressure 100 kPa and its mass is 0 76 gm Calculate the masses of hydrogen and oxygen present in the mixture

65 1 kg ice at 20 C is mixed with 1 kg steam at 200 C The equilibrium temperature and mixture content is a 80 C and mixture content 2 kg b 110 C and mixture content 2 kg steam c 100 C and mixture content 24 kg water 17 d 100 C and mixture content 34 kg water 10 17 kg steam and 20 27 kg steam and

c 1500 cal 200 C d 1000 cal 200 C 0 4 kg of ice at 15 C are added to 5 kg of water at 15 C The temperature of the resulting mixture equals a 15 C b 0 C c 5 C d 15 C

Illustration 5 If the pressure of a gas contained in closed vessel is increased by 0 5 when heated by 2 C then the initial temperature must be

80 g of water at 30 C are poured on a large block of ice at 0 C The mass of ice that melts is a 30 g b 80 g d 150 g c 1600 g

41 If 1 g of steam is mixed with 1 g of ice then the resultant temperature of the mixture is a 270 C b 230 C c 100 C d 50 C

4 gm of steam at 100 C is added to 20 gm of water at 46 C in a container of negligible mass Assuming no heat is lost to surrounding the mass of water in container at thermal equilibrium is Latent heat of vaporisation 540 cal gm Specific heat of water 1 cal gm C a 18 gm b 20 gm

The spectrum of a black body at two temperature 27 C and 327 C is shown in the figure Let A and A be the areas under the two curves respectively The value of A

When 0 400 kg of water at 30 C is mixed with 0 150 kg of water at 25 C contained in a calorimeter the final temperature is found to be 27 C find the water equivalent of the calorimeter a 0 450 kg c 0 50 kg b 1 kg d 1 5 kg

Bottom of a lake is at 0 C and atmospheric temperature is 20 C If 1 cm ice is formed on the surface in 24 h then time taken to form next 1 cr of ice is 1 24 h 2 72 h 4 96 p

Solid A with mass M is at its melting point TA It is placed in thermal contact with solid B with heat capacity C and initially at temperature TB TB T The combination is thermally isolated A has latent heat of fusion L and when it has melted has heat capacity C If A completely melts the final temperature of both A and B is A CATA CBTB ML CA C C CATA CBTB ML CA CB B CATA CBTB ML CA C D CAT CT ML C C

In the figure shown AB is a rod of length 30 cm and area of cross section 1 0 cm and thermal conductivity 336 S I units The ends 20 c A B are maintained at temperatures 20 C and 40 C respectively A point C of this rod is connected to a box D containing ice at 0 C through a highly conducting wire of negligible heat capacity The ate at which ice melts in the box is Assume latent heat of fusion or ice L 80 cal gm A 84 mg s B 84 g s C 20 mg s 10cm Ice D 0 C B D 40 mg s 40 C 20cm highly conducting wire

A copper ball of mass 100 gm is at a temperature T It is dropped in a copper calorimeter of mass 100 gm filled with 170 gm of water at room temperature Subsequently the temperature of the system is found to be 75 C T is given by Given room temperature 30 C specific heat of copper 0 1 cal gm C 2017 1 825 C 3 885 C 2 800 C 4 1250 C

substance is cooled by a constant power source Assuming there is urrounding Its temperature vs time graph is shown The value of Solid Si liquid A 2 3 3 T C 100 C 70 C 50 C 10 C 10 20 40 B 3 6 2 80 100 C 2 6 3 no heat loss to the S t s D 1 3 2 gas

The temperature of ice is 10 C specific heat 0 5 kca kg C and that of water 60 C They are mixed in equal amounts What part of the ice will be meked 10 C 09ce 1 water 0 C 0 C que 1 th 6 2 3 11 th mSAT 16 Whole of it will be melted 37 432 540x80 43200 1000 x 80

14 2 gm of steam condenses when passed through 40 gm of water initially at 25 C The condensation of ste raises the temperature of water to 54 3 C What is the latent heat of steam 1 540 cal g 2 536 cal g 3 270 cal g 4 480 cal g

33 An electric immersion heater of 1 08 kW is immersed in water After the water has reached temperature of 100 C how much time will be required to produce 100 g of steam 1 210 s 2 105 s 4 50 s 3 420 s Hint Pt H 1 08 x 10 t 100 x 540 x 4 2

Ice at 20 C is filled upto height h 10 cm in a uniform cylindrical vessel Water at temperature 0 C is filled in another identical vessel upto the same height h 10 cm Now water from second vessel is poured into first vessel and it is found that level of upper surface falls through Ah 0 5 cm when thermal equilibrium is reached Neglecting thermal capacity of vessels change in density of water due to change in temperature and loss of heat due to radiation calculate initial temperature 0 of water Given Density of water P 1 gm cm Specific heat of water s1 cal gm C Specific latent heat of ice L 80 cal gm Density of ice P 0 9 gm cm Specific heat of ice 0 5 cal gm C

Two taps supply water to a container one at the temperature of 20 C at the rate of 2 kg minute and another at 80 C at the rate of 1 kg minute If the container gets water from the two taps simultaneously for 10 minutes then the temperature of water in the container is A 35 C B 30 C C 50 C D 40 C E 45 C

20 Steam at 100 C is passed into 100 g of ice at 0 C Finally when 80 g ice melts the mass of water present will be Latent heat of fusion and vapourization are 80 cal g and 540 cal g 1 respectively specific heat of water 1 cal g C 1 80 g 2 100 g 3 90 g 4 75 g

6 How much minimum amount of ice at 0 C is require to condense 100 g steam at 100 C 2 600 g 4 475 g 1 675 g 3 300 g

Q 6 identical rods made up of two different materials are connected as shown then calculate the temperature of junction B AN 60 CD A B RANSEK D y 10 C E 4 W SICS VONCS

7 10 gm of ice at 20 C is dropped into a calorimeter containing 10 gm of water at 10 C the specific heat of water is twice that of ice When equilibrium is reached the calorimeter will contain a 20 gm of water b 20 gm of ice c 10 gm ice and 10 gm of water f water 116

Example 16 21 100 g ice at 0 C is mixed with 10 g steam at 100 C Find the final temperature and composition

17 Water falls from a height 500 m What is the rise in temperature of water at bottom if whole energy remains in the water 1 0 96 C 3 1 16 C 18 Latent heat of ion in 2 1 02 C 4 0 23 C

Heat required to heat water from 0 C to 20 C Total heat required Solution 0 04 x 4200 20 1680 13440 3360 18480 J Illustration 16 Steam at 100 C is passed into 1 1 kg of water contained in a calorimeter of water equivalent 0 02 kg 15 C till the temperature of the calorimeter and its contents rises to 80 C What is the mass of steam condense Latent heat of steam 536 cal g

3 When 100 g of boiling water at 100 C is added into a calorimeter containing 300 g of cold water at 10 C temperature of the mixture becomes 20 C Then a metallic block of mass 1 kg at 10 C is dipped into the mixture in the calorimeter After reaching thermal equilibrium the final temperature becomes 19 C What is the specific heat of the metal in C G S unit A 0 01 B 0 09 R 0 1 0 3