Answer to Question #114583 in General Chemistry for Alana M

Question

Calculate the energy (in kJ) required to heat a beaker of water at 21.9 oC to the boiling point (100oC). The mass of the water is 49.0 g. The specific heat of water is 4.184 J/goC. Round your answer to one place past the decimal.

Answer 1

Solution:

The energy required to heat an object is given by the formula:

Q = m × C × ΔT

where

Q is the energy required;

m is the mass;

C is the specific heat capacity;

ΔT is the change in temperature.

In this problem:

m(H₂O) = 49.0 g

C(H₂O) = 4.184 J/g°C

ΔT = T_final - T_initial = (100°C - 21.9°C) = 78.1°C

Therefore,

Q = m × C × ΔT = (49.0 g) × (4.184 J/g°C) × (78.1°C) = 16011.75 J = 16.0 kJ

Q = 16.0 kJ

Answer: 16.0 kJ is the energy required.