Advertisements
Advertisements
प्रश्न
How much heat energy is necessary to raise the temperature of 5 kg of water from 20°C to 100°C?
How much heat energy is necessary to raise the temperature of 5 kg of water from 20°C to 100°C? [c = 1 kcal/kg°C]
Advertisements
उत्तर
Given: Mass (m) = 5 kg, specific heat of water (c) = 1 kcal/kg °C
Change in temperature (ΔT) = 100 − 20
= 80°C
According to the principle of heat exchange,
Energy supplied to water = Energy gained by water
= Mass of water × specific heat of water × rise in the temperature of water
Q = mc ΔT
Q = 5 × 1 × 80
= 400 kcal
The heat energy necessary to raise the temperature of the water is 400 kcal.
APPEARS IN
संबंधित प्रश्न
A geyser heats water flowing at the rate of 3.0 litres per minute from 27 °C to 77 °C. If the geyser operates on a gas burner, what is the rate of consumption of the fuel if its heat of combustion is 4.0 × 104 J/g?
Water is used in hot water bottles for fomentation. Give a reason.
Give one example where high specific heat capacity of water is used as cooling purposes?
Ice cream appears colder to the mouth than water at 0℃. Give reason.
Give three reasons for the increase of green house gases.
Study the following procedure and answer the questions below:
1. Take 3 spheres of iron, copper and lead of equal mass.
2. Put all the 3 spheres in boiling water in a beaker for some time.
3. Take 3 spheres out of the water. Put them immediately on a thick slab of wax.
4. Note, the depth that each sphere goes into the wax.
i) Which property of substance can be studied with this procedure?
ii) Describe that property in minimum words.
iii) Explain the rule of heat exchange with this property.
Define heat capacity.
A burner raises the temperature of 360 g of water from 40°C to 100°C in 5 minutes. Calculate the rate of heat supplied by the burner.
What are other units of heat? Name and define them.
m kg of a substance of specific heat capacity s J/kg °C is heated so that its temperature rises from θ1°C to θ2°C. Write down the expression for the heat Q supplied.
Explain, why water is considered as best liquid for quenching thirst?
If substances A and B are liquids then which one would be more useful in car radiators?
Given: Specific heat capacity’A’ 3.8 J/g /K. Specific heat capacity ‘B’ 0.4 J/g /K.
1 kg of water freezes to form ice at 0°C. What amount of heat is withdrawn?
Explain why the specific heat capacity at constant pressure is greater than the specific heat capacity at constant volume.
50 g of copper is heated to increase its temperature by 10° C. If the same quantity of heat is given to 5 g water, the rise in its temperature is [Specific heat of copper = 420 joule-kg-1 °C-1 , specific heat of water = 4200 joule-kg-I °C-1]
A monoatomic gas of pressure 'P' having volume 'V' expands isothermally to a volume '2V' and then adiabatically to a volume '16V'. The final pressure of the gas is ______.
(ratio of specific heats = `5/3`)
When two kilocalories of heat are supplied to a system, the internal energy of the system increases by 5030 J and the work done by the gas against the external pressure is 3350 J. Calculate J, the mechanical equivalent of heat.
