Calculate the amount of energy (in kilojoules) needed to heat 346 g of liquid water from –10 °C to 182°C. Assume that the specific heat of water is 4.184 J/g · °C for liquid and that the specific heat of steam is 1.99 J/g · °C.

Answer : The amount of heat required is,

Solution :

The process involved in this problem are :

The expression used will be:

where,

= heat required for the reaction

m = mass of ice = 346 g

= specific heat of solid water or ice =

= specific heat of liquid water =

= specific heat of gaseous water =

= enthalpy change for fusion =

= enthalpy change for vaporization =

Now put all the given values in the above expression, we get:

Therefore, the amount of heat required is,