enthalpy changes in solution

Question 1

why are ionic lattices soluble?

Answer 1

water molecules overcome the strong electrostatic forces between oppositely charged ions

Question 2

define ‘enthalpy change of solution’ in terms of enthalpy

Answer 2

enthalpy change that takes place when one mole of a solute dissolves in a solvent

Question 3

is enthalpy change of solution endo/exothermic?

Answer 3

can be both

Question 4

how is enthalpy calculated?

Answer 4

mass x temp change x 4.18
divide by 1000
divide by moles

Question 5

what two processes take place when a solid ionic compound dissolves in water?

Answer 5

• ionic lattice breaks up
• water molecules are attracted to and surround the ions

Question 6

what is meant by ‘enthalpy change of hydration’?

Answer 6

• enthalpy change when 1 mole of gaseous ions dissolves
• separate gaseous ions interacting with polar molecules to form hydrated aqueous ions