This document defines key terms related to chemical energetics and thermodynamics. It discusses exothermic and endothermic reactions, heat of formation, standard heat of formation, and enthalpy. It also provides multiple choice questions to test understanding of these concepts, such as identifying whether photosynthesis is an exothermic or endothermic reaction.

1. Chapter 10
Chemical Energetics
(The failure is the result of disobedience of
first parents then teachers and finally of
the Almighty Allah)

2.  Definitions
1. Thermodynamics: -The study of conversion
and conservation of heat and other forms of
energy is called thermodynamics.
2. Thermochemistry: - it deals with the
measurement or calculation of heat absorbed or
abandoned in chemical reactions.
3. Thermo chemical reactions: - the chemical
reactions which are accompanied by energy
changes along with the material changes are
generally known as thermochemical reactions.
4. Exothermic reactions: -the chemical reactions
which are accompanied by the liberations or
emission of energy are called exothermic
reactions.
5. Endothermic reactions: -the chemical
reactions which are accompanied by the
absorption of energy are called endothermic
reactions.
6. system: -the collection of matter having certain
boundaries is called system
7. Surroundings:- the environment of a system or
the thing that affect on a system are included in
surroundings.

3. 8. Heat of formation: - the change of enthalpy
when one gram mole of a substance is formed
from its elements
9. Standard heat of formation: -the change of
enthalpy when one gram mole of a substance is
formed from its elements at 25o
C and 1 atm is
called standard heat of formation.
10. Enthalpy: -the total heat content of a system is
called enthalpy..
11. Heat of neutralization: - The amount of heat
released during the neutralization process when
one mole of water is produced by the reaction of
acid and base.

4.  Multiple Choice Questions
1. Thermochemical reactions involve:
a) material changes b) energy changes
c) both a & b d) heat changes
2. EXO means:
a) out of or to evolve b) into or to absorb
c) outside d) heat
3. ∆H negative represents which reaction:
a) thermochemical b) exothermic
c) endothermic d) chemical
4. Formation of water from hydrogen and oxygen
produces energy:
a) -286 K.J/mole b) +286 K.J/mole
c) -393 K.J/mole d) +393 K.J/mole
5. ∆H positive represents neutralization:
a) true b) false
6. Acid Base reaction is called neutralization
reaction:
a) true b) false
 Questions 7 – 12
• Select from the terms below:
A) endothermic reaction B)exothermic reaction
7. photosynthesis

5. 8. respiration
9. decomposition reaction
10. bond formation
11. combustion
12. melting of ice
The Book MCQs
13. in an exothermic reaction:
a) heat energy is lost b) heat energy is gained
c) both a & b d) N.O.T
14. In an exothermic reaction:
a) container becomes hot
b) container becomes cold
c) the temperature of container remains same
d) N.O.T
15. During an endothermic reaction:
a) container becomes cold
b) container becomes hot
c) the temperature of container remains same
d) N.O.T
1 C 2 A 3 B
4 A 5 B 6 A
7 A 8 B 9 A
10 B 11 B 12 A
13 A 14 A 15 A