This document discusses measurement of thermal changes and calorimetry. It explains that heat is energy in transit that transfers between bodies due to temperature differences. Calorimetry involves using calorimeters to contain heat and measure heat changes using principles like Q=mcΔT, where Q is heat, m is mass, c is specific heat, and ΔT is change in temperature. The document also addresses problems and solutions in accurately measuring heat changes in chemical and physical processes using calorimetry.

2.  Name: Syed Ahmed
Khizar
 Teacher: Sir Asif Imran
 Course: TXCH-101
 Topic:
Measurement Of Thermal
Changes

3. Measurement Of Thermal
Changes
Heat
“Energy in Transit.”
“E” which trasfers from
one body to another
due to temperature
difference.

4. Measurement Of Thermal
Changes
Calorimetry
Calorie = Heat = Therm

5. Law Of Heat Exchange
Amount Of Heat
Released
Amount Of Heat
Absorbed
=
Qreleased = Qabsorbed
Q = mc△T
Q = nc△T
Q = c△T
Specific Heat
Molar Heat Capacity
Molar Heat Capacity
Heat Released or
Absorbed By A Body:

6. Problem
 For every process:
 Every substance have d/f value of “c”.
 Impossible for unknown substance.
Chemical
Or
Physical
Heat changes
occur

7. Easy Solution
 Do the process in
water.
 Why?
Process Water
Qprocess = Qwater
Another
Problem
Environment

8. Solution
Open System M E
Close System M E
Isolated System M E
System

9. Calorimeter
Not a measuring instrument.
Used to keep heat inside.

10. Container also absorb heat.
Another Problem
Qprocess = Qwater + Qcontainer

11. Qprocess = Qwater + Qcontainer
Qprocess = mwcw△T + mccc△T
How to take reading?
1)Mc
2)Mw
3)Ti
4)Tf
Qprocess = mwcw(Tf-Ti)+ mccc(Tf-Ti)
Readings
Balanc
e
Thermomete
r