1) 2 kg of iron at 80°C is placed in a copper can of mass 0.5 kg containing 1 kg of water at 20°C. After stirring, the temperature of the mixture is 30°C. Calculate the specific heat capacity of iron.
2) Calculate the amount of heat taken by 1 kg of ice at 0°C to convert into boiling water at 100°C.
3)When 50 calorie heat is supplied to 30g of a substance, its temperature is observed to increase from 15°C to 40°C. What is (a) the heat capacity and (b) the specific heat capacity of the substance?
pls answer these 3 questions ...
Answers
Answer:
Mass of the metal, m = 0.20 kg = 200 g
Initial temperature of the metal, T
1
= 150
o
C
Final temperature of the metal, T
2
= 40
o
C
Calorimeter has water equivalent of mass, m = 0.025 kg = 25 g
Volume of water, V = 150 cm
3
Mass (M) of water at temperature T = 27
o
C:
150×1=150g
Fall in the temperature of the metal:
ΔT
m
=T
1
-T
2
=150−40=110
o
C
Specific heat of water, C
w
=4.186J/g/K
Specific heat of the metal =C
Heat lost by the metal, =mCT .... (i)
Rise in the temperature of the water and calorimeter system: T
1
−T=40−27=13
o
C
Heat gained by the water and calorimeter system: =m
1
C
w
T=(M+m)C
w
T ....(ii)
Heat lost by the metal = Heat gained by the water and colorimeter system
mCΔT
m
=(M+m)C
w
T
w
200×C×110=(150+25)×4.186×13
C=(175×4.186×13)/(110×200)=0.43Jg
−1
k
−1
If some heat is lost to the surroundings, then the value of C will be smaller than the actual value.