Energetics Flashcards
1
Q
Types of reactions that are exothermic:
A
Combustion
Reactions of metals with acid
Many oxidation reactions
Most neutralization reactions (except those with weak acids/alkalis)
2
Q
Types of reactions that are endothermic:
A
Thermal decomposition reactions
Neutralization: citric acid and sodium bicarbonate
acetic acid and sodium bicarbonate
3
Q
What is heat enthalpy change?
A
The change in heat energy for a chemical reaction at a constant pressure
4
Q
Unit of enthalpy change:
A
kJ/mol
5
Q
Unit of s.h.c:
A
J/g/⁰C
6
Q
Errors in the calorimetry experiment (not combustion):
A
- Heat lost to surroundings
- Neglecting the s.h.c of the calorimeter
- Approximating the s.h.c of the solution
- Density of the solution is assumed to be the same as water
- Reaction may be incomplete/slow
7
Q
Energy in terms of bond metabolism:
A
- Energy is needed to break bonds
- Energy is released when new bonds are made
8
Q
What is bond energy?
A
The amount of energy needed to break 1 mol of covalent bonds in gaseous molecules
