Investigation of Action of Saliva and 3 M Hydrochloric Acid in Two Carbohydrate Solutions

2543 Words Feb 4th, 2016 11 Pages
Centre for Foundation Studies, UTAR

1

2

Chapter Scopes
• Endothermic & Exothermic reactions
• Enthalpy changes: ∆H of formation, combustion, hydration, neutralization, atomization. CHAPTER 5

Chemical Energetic /
Thermochemistry

• Lattice energy, electron affinity
• Heat of fusion and vaporization
• Hess’ Law
• Born-Haber cycles
• Calorimetry

© 2006 Brooks/Cole - Thomson

© 2006 Brooks/Cole - Thomson

3

Energy & Chemistry

4

Thermochemistry
• Thermochemistry is the study of heat (energy) change/transfer in a chemical reaction.

• ENERGY is the capacity to do work or transfer heat. • HEAT is the transfer of thermal energy between two objects because of their difference in temperature.

Heat
…show more content…
1000 cal = 1 kilocalorie = 1 kcal

Specific Heat Capacity, Cs
But we use the unit called the
JOULE
1 cal = 4.184 joules

The amount of heat (q) required to raise the T of
1 gram of the substance by 1 C or 1 K

James Joule
1818-1889

© 2006 Brooks/Cole - Thomson

Specific Heat Capacity, Cs
• How much energy is transferred due to T difference?
• The heat (q) ―lost‖ or ―gained‖ is related to

© 2006 Brooks/Cole - Thomson

11

Change in Temperature (T)
T of
System

Sign of
Tsystem

Sign of q

Direction of Heat
Transfer

Increase

+
Tfinal >Tinitial

+

Decrease

-

-

Heat transferred from surroundings to system
(_____thermic)
Heat transferred from system to surroundings (_____thermic)

a) sample mass
b) change in T and
c) specific heat capacity

Tfinal  Tinitial

Specific heat capacity = heat lost or gained by substance (J)
(mass, g)(T change, K)
© 2006 Brooks/Cole - Thomson

FHSC1114 Physical Chemistry

12

© 2006 Brooks/Cole - Thomson

2

Centre for Foundation Studies, UTAR

Heat Transfer

13

q = m x Cs x T q = C x T






14
Example 1: If 25.0 g of Al cool from 310oC to 37oC, how many joules of heat energy are lost by the Al?

(specific heat capacity of Al = 0.897 J g-1 K-1)
Solution:

q = heat absorbed or released (J)
Cs = specific heat (J g-1 K-1)
C = heat capacity (J

Related Documents

This Way of Life Essay | Sol a Pino (Zvizdan) 2016 | Hayate no Gotoku 3nd Season – Todos os Episódios