Glycerol is widely used in pharmaceutical manufacturing
PHYSICS · Multi-part · CBSE · Physics · Thermal Properties of Matter · Thermal Properties of Matter
Problem
Glycerol is widely used in pharmaceutical manufacturing. A 120 g sample of glycerol at 25 °C must be heated to 75 °C in a jacketed vessel. The specific heat capacity of glycerol depends on temperature and may be assumed to be 2.4 J g⁻¹ °C⁻¹ from 20 °C to 50 °C and 2.7 J g⁻¹ °C⁻¹ from 50 °C to 80 °C. During the heating operation, 25 % of the electrical energy supplied to the jacket is lost to the surroundings.
(a) Calculate the energy required to raise the temperature of the glycerol from 25 °C to 50 °C.
(b) Calculate the energy required to raise the temperature of the glycerol from 50 °C to 75 °C.
(c) Determine the total thermal energy that must be delivered to the glycerol.
(d) Taking into account the 25 % energy loss, calculate the total electrical energy that must be supplied by the heating system.