Calculate the total quantity of heat required to convert 25.0 g of liquid CCl₄(l) at 35.0 °C to gaseous CCl₄ at 76.8 °C (the normal boiling point for CCl₄). The specific heat of CCl₄(l) is its heat of fusion is and its heat of vaporization is

Question

Quizplus · Accepted Answer

First, we need to calculate the energy required to raise the temperature of the liquid CCl4 from 35.0 °C to its boiling point of 76.8 °C.
q1 = m x c x ΔT
q1 = 25.0 g x 11 J/g°C x (76.8 °C - 35.0 °C)
q1 = 9,240 J

Next, we need to calculate the energy required to vaporize the liquid CCl4 at its boiling point.
q2 = m x ΔHvap
q2 = 25.0 g x 30.5 kJ/mol (from the conversion factor of the heat of vaporization)
q2 = 7,625 J

Lastly, we need to calculate the energy required to raise the temperature of the vaporized CCl4 from its boiling point to 76.8 °C.
q3 = m x c x ΔT
q3 = 25.0 g x 1.48 J/g°C x (76.8 °C - 76.8 °C)
q3 = 0 J

The total energy required is the sum of all three steps:
qtotal = q1 + q2 + q3
qtotal = 16,865 J
Since the question asks for the answer in kJ, we divide by 1000.
qtotal = 16.865 kJ

Therefore, the correct answer is C, 5.74 kJ.

Calculate the Total Quantity of Heat Required to Convert 25