Enthalpy changes for solid + solution

Question 1

what is hess’s law

Answer 1

the energy change of any reaction is the same, regardless of route taken

Question 2

where is more chemical energy present in an exothermic reaction

Answer 2

reactants > products

Question 3

where is more chemical energy present in an endothermic reaction

Answer 3

reactants < products

Question 4

which ways do the arrows point in enthalpy of formation

Answer 4

up

Question 5

which ways do the arrows point in enthalpy of combustion

Answer 5

down

Question 6

what are the standard conditions

Answer 6

• 298K
• 1mol/dm³ conc
• 1atm

Question 7

what is enthalpy of solution used for

Answer 7

indicates if a substance should dissolve

Question 8

how to calculate enthalpy of solution

Answer 8

= lattice - hydration

Question 9

what does a negative enthalpy of solution mean

Answer 9

it should be spontaneously soluble at that temperature
stable

Question 10

what does a small positive enthalpy of solution mean

Answer 10

will dissolve as energy is used from solution
unstable

Question 11

what does a large positive enthalpy of solution mean

Answer 11

unlikely to dissolve at that temperature
unstable

Question 12

increased temperature =

Answer 12

increased solubility

Question 13

what are the 5 steps of Born Haber Cycles

Answer 13

….enthalpy of formation
(ionic solid)
1. atomisation
2. Ionisation
3. Atomisation

4. Electron affinity
5. Lattice formation