22.2 Enthalpy Changes In Solution

Question 1

What is the standard enthalpy change of solution?

Answer 1

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

Question 2

If the solvent is water, what happens after the enthalpy change of solution?

Answer 2

Ions from the ionic lattice finish surrounded with water molecules as aqueous ions

Question 3

Which ions are the partially charged water molecules attracted to?

Answer 3

Partially positive hydrogens attracted to the negative ion
Partially negative oxygens attracted to the positive ion

Question 4

What is enthalpy change of hydration?

Answer 4

The enthalpy change that takes place when gaseous ions dissolve in water to form one mole of aqueous ions

Question 5

Is enthalpy change of solution exo or endothermic?

Answer 5

Both

Question 6

Is enthalpy change of hydration exo or endothermic?

Answer 6

Both

Question 7

What happens when a solid ionic compound dissolves in water?

Answer 7

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

Question 8

What is route one of the graph that is used to calculate lattice enthalpy?

Answer 8

• Gaseous ions -> ionic lattice (lattice enthalpy)
• Ionic lattice –> aqueous ions (enthalpy change of solution)

Question 9

What is route two of the graph that is used to calculate lattice enthalpy?

Answer 9

Gaseous ions –> aqueous ions (enthalpy change of hydration)

Question 10

When calculating enthalpy change, which species’ mass do you use?

Answer 10

The mass of whatever is changing temperature