Question

1. Calculate the amount of heat required for 25.0 grams of water tochange from 10 degrees Celsius to 30 degrees Celsius.

2. 50.0 grams of water at 100 degrees Celsius evaporated to water vapor 2 points
at 100 degrees Celsius. Calculate the amount of heat required for this
conversion.

3. A student measured 15.0 grams of ice in a beaker. The beaker was then
placed on a hot plate where it was heated uniformly for a certain amount
of time. During the melting process of the ice, the student noted that the
temperature was at 0 degree Celsius. When all the ice converted to water,
the final temperature was also at 0 degree Celsius. How much heat was
used to melt the ice?

4. If 5.0 grams of water was cooled from 50 degrees Celsius to 40
degrees Celsius, then calculate the amount of heat released by the water.

5. A certain amount of water used exactly 84.0 Joules of heat energy to
change from 25.0 degrees Celsius to 35 degrees Celsius. How many
grams of water was used?


Please help me

Answer 1

Step-by-step explanation:

1 )

amount of heat required = mass x specific heat x rise in temperature

= 25 x 4.2 x 20 = 2100 J .

2 )

Amount of heat required

= mass x latent heat of vaporisation

= 50 x 2260 = 113000 J .

3 )

Amount of heat required in melting the ice

= mass x latent heat of fusion

= 15 x 336 = 5040 J

4)

heat released in cooling water

= mass x specific heat x fall in temperature

= 5 x 4.2 x 10

= 210 J

5 )

amount of heat required = mass x specific heat x rise in temperature

84 = mass x 4.2 x 10

mass = 2 grams .