University:
Concordia University Wisconsin
Course:
PHYS 1524 | General Physics II
Academic year:

2023
Views:

208

Pages:

2
Author:

Carissa Thomas

CALORIMETRY 1 cal = 4.186 J ; 4.2 J 1. Thermal capacity of a body = QT Amount of heat required to raise the temp. of a given body by 1°C (or 1K) 2. Specific heat capacity = Q (m = mass) mT Amount of heat required to raise the temperature of unit mass of a body through 1°C (or 1K) 3. Molar heat capacity = 4. Water equivalent Q (n = number of moles) n T If thermal capacity of a body is expressed in terms of mass of water, it is called water equivalent. Water equivalent of a body is the mass of water which when given same amount of heat as to the body, changes the temperature of water through same range as that of the body. Therefore water equivalent of a body is the quantity of water, whose heat capacity is the same as the heat capacity of the body. Water equivalent of the body, Unit of water equivalent is g or kg. 5. Latent Heat (Hidden heat) : The amount of heat that has to supplied to (or removed from) a body 6. Principle of calorimetry for its complete change of state (from solid to liquid, liquid to gas etc) is called latent heat of the body. Remember that phase transformation is an isothermal (i.e. temperature = constant) change. Heat lost = heat gained For temperature change Q = msT, For phase change Q = mL 7. Heating curve If to a given mass(m) of a solid, heat is supplied at constant rate (Q) and a graph is plotted between temperature and time, the graph is called heating curve. THERMAL PROPERTIES OF MATTER Specific heat (or thermal capacity)  1 slope of curve Latent heat  length of horizontal line 8. Specific heat of a body may be greater than its thermal capacity as mass of the body may be less than unity. 9. The steam at 100°C causes more severe burn to human body than the water at 100°C because steam has greater internal energy than water due to latent heat of vaporization. 10. Heat is energy in transit which is transferred from hot body to cold body. 11. One calorie is the amount of heat required to raise the temperature of one gram of water through 1°C (more precisely from 14.5°C to 15.5°C). 12. Clausins & clapeyron equation (effect of pressure on boiling point of liquids & melting point of solids related with latent heat) dP L  dT T(V2  V1 )