Chapt 6 Chemical Energetics

Question 1

Relationship between heat capacity and specific heat capacity eqn

Answer 1

C = mc
C is heat capacity
c = Specific heat capacity
m = mass of solution

Question 2

Formula of heat absorbed/released

Answer 2

heat absorbed/released = mc(delta T)

Question 3

General formula for enthalpy change

Answer 3

+/- (Heat absorbed/released)/(moles of limiting reagent)

Question 4

Why is a temp correction graph more accurate?

Question 5

Formula for enthalpy change during neutralisation

Question 6

Formula for enthalpy change during combustion

Question 7

Describe traits of endo & exo thermic rxcns

Answer 7

ENDO THEN EXO
- Heat is absorbed/evolved from (surroundings to reactants/reactants to surroundings)
- Surrounding temp (decreases/increases)
- Products have a (higher/lower) enthalpy than reactants so products are (less/more) energetically stable
- Enthalpy change is (+/-)

Question 8

What are the conditions when calculating enthalpy change?

Answer 8

standard conditions
- 25C or 298K
- 1 bar or 10^5 Pa
- reactants in their most stable form

Question 9

EXCEPTION: Which combustion rxcn is endothermic?

Answer 9

N2