QUANTITY OF HEAT REVISION

Define heat

• Quantity of temperature in a body

• form of energy that is transferred from a body at high temperature to a body at low temperature

• degree of hotness or coldness of a body

the following factors affect the rate of evaporation. which one does not?

• temperature

• surface area

• draught

• humidity

the quantity of heat required to change a material from solid to liquid without change in temperature is called

• latent heat

• latent heat of fusion

• specific latent heat of fusion

0.1kg of dry ice at 0⁰C is melted in a 0.5kg of water at 20⁰C in a calorimeter of mass 0.25kg. if the final temperature of the mixture is 10⁰C, how much heat was lost by the water? take C_w=4200J/Kg/K

• 21000 J
• 42000 J
• 84000 J
• 168000 J

What quantity of heat is required to raise the temperature of 450 grams of water from 15°C to 85°C? The specific heat capacity of water is 4200 J/kg/k.

• 132300 J

• 150000 J
• 120000 J
• 131670 J

the quantity of heat required to change a unit mass of a substance from solid to liquid without change in temperature is called

• specific Latent Heat of fusion

• Specific Heat Capacity
• Latent Heat of Fusion

• specific latent heat of vaporization

the following factors affect the boiling and melting points of a substance. which one does not?

• pressure

• impurities

• temperature

• wind

An electric heater supplied a current of 2.0A to raise the temperature of 2kg of water by 8⁰C after 15 minutes. if the voltmeter reading was 24V, calculate the electrical heat energy supplied

• 72000 J
• 43200 J

• 36000 J
• 24000 J

what is temperature?

• A degree of the hotness or coldness of an object or substance with reference to a standard value

• feeling hot or cold

• when the sun is hot

• A type of vehicle

A block of mass 2.5kg is heated from 30⁰C to 55⁰C in 10 minutes by an electric heater rated 45W. find the heat capacity of the block?

• 1080J/K

• 150 J/K
• 200 J/K
• 250 J/K