Question

How much heat is required to change 100 g of ice (H2O) at 253 K to vapor (steam) at 393 K?

Answer 1

Answer: The heat required will be 58.604 kJ.

Explanation:

To calculate the amount of heat required, we use the formula:

$Q= m\times c\times \Delta T$

Q= heat gained  or absorbed = ? J

m = mass of the substance = 100 g

c = heat capacity of water = 4.186 J/g ° C

Putting values in above equation, we get:

$\Delta T={\text{Change in temperature}}=(393-253)K=140K=140^oC$

$Q=100g\times 4.186J/g^oC\times 140^oC$

Q = 58604 Joules  = 58.604 kJ     (Conversion factor: 1 kJ = 1000J)

Thus, heat released by 100 grams of ice is 58.604kJ.