energy

What is the quantity of energy which is equivalent to 50 kJ ?

• 0.05 J

• 500 J

• 5x 10⁴J

• 5× 10³

Kilocalorie is from energy units which equals ..........

• 4180 J

• 41.8 kJ

• 4.18 J

• 418 J

Specific heat of water is higher than that of mercury, which of the following statements does not agree with the previous information?

• The quantity of heat required to raise the temperature of 10 g of water by 15°C is higher than that required to raise the temperature of the same mass of mercury

  by the same degrees.

• The quantity of heat released by lowering the temperature of 20 g of water by

  10°C is higher than that released by lowering the temperature of the same mass of mercury by the same degrees.

• The quantity of heat released by lowering the temperature of 100 g of water from

  80°C to 20°C equals the quantity of heat released by lowering the temperature of

  the same mass of mercury from 80°C to 20°C

• By heating two equal masses of water and mercury, both have the same initial temperature, with the same quantity of heat, the final temperature of mercury will be higher than that of water.

If the temperature of a substance is doubled as well as its mass, its specific heat

will be

• decreased to quarter.

• increased to double.

• constant.

• increased to four times

If two bodies have the same mass, gain the same quantity of heat, and the raise in the temperature of the second body is double that of the first, therefore

the specific heat of the second body is --------the first one.

• half

• quarter

• double

• equal to

All the following can be identified by knowing the specific heat of metals, except -----------

• a the quantity of heat needed to raise the temperature of 10 g of a metal by 10 c

• the quantity of heat released by cooling 10 g of a metal from 100°C to 25°C

• internal energy of metal.

• the gram atomic mass of the metal.

A sample of water its mass equals 100 g, its initial temperature is 22°C, this sample acquired a quantity of heat which equals 8360 J, what is the final temperature of the sample?

• 18.3

• 20

• 25.7

• 42

What is the temperature of the mixture formed of 100 g of water with temperature 15°C and 250 g of water with temperature 50°C in a supposedly isolated position ?

• 31.4

• 40

• 44

• 50

The bomb calorimeter is used to measure the heat of combustion of some

substances ........

• under normal atmospheric pressure.

• at 100°C

• at 25°C

• under high pressure.