Water (2510 g ) is heated until it just begins to boil. if the water absorbs 5.09×105 j of heat in the process, what was the initial temperature of the water?

Ans: Initial temperature of water = 51.5 C

Given:

Mass of water (m) = 2510 g

Heat absorbed by water (q) = 5.09*10⁵ J

Final temperature of water = boiling point = T2 = 100 C

To determine:

The initial temperature, T1

Explanation:

Heat absorbed by water is given as:

q = mc(T2-T1)

c = specific heat of water = 4.18 J/gC

5.09*10⁵ = 2510 g*4.18 J/gC *(100-T1)

T1 = 51.5 C

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.