(L2) Module 1 L2 - Aqueous Solutions

Question 1

What is a electrolyte?

Answer 1

Dissolves to give ions in a solution. e.g, NaCl

Question 2

What is a non-electrolyte?

Answer 2

Doesn’t dissolve to form ions. e.g, glucose

Question 3

What is a solution?

Answer 3

A solution is formed when 1 or more chemical dissolves in a liquid

Question 4

What is a solvent?

Answer 4

A liquid in which the solute dissolves.

Question 4

What is a solute?

Answer 4

Substance that dissolves in a liquid. Can be a solid, liquid, or gas.

Question 5

What do electrolytes include?

Answer 5

All ionic solids, bases, acids

Question 6

Traits of a strong electrolyte.

Answer 6

• Undergo complete dissociation in water
• Even ionic solids which aren’t very soluble (AgCl) are strong electrolytes as they dissociate completely

Question 7

Traits of a weak electrolyte.

Answer 7

• Undergo incomplete dissociation in water
• When dissociated, most of dissolved species are molecules
• These molecules may then dissociate further into ions
• Here, reaction doesn’t go ‘to completion.’

e.g weak acids, weak bases.

Question 8

What does electronegativity mean?

Answer 8

It means some atoms have a greater share of electrons due to their more highly electronegative nature.

This may result in the formation of bond dipoles.

Question 9

What are bond dipoles?

Answer 9

One atom has a greater share of electrons due to electronegativity differences, resulting in one atom with greater share being more negative while the other atom with less electron share is more positive.

Question 10

What is covalent bonding?

Answer 10

2 atoms connected by the shared eletrons between them

Question 11

What is hydrogen bonding?

Answer 11

Hydrogen in one molecule is attracted to an electronegative atom in another molecule (F, O, N)

Question 12

How strong are dipole-dipole bonds?

Answer 12

Usually pretty weak. Specific combinations such as H2O-H2O can be incredibly strong. This results in a higher MP/BP.

Question 13

Weird traits of water: Surface tension, heat capcity, effect of pressure on freezing:

Answer 13

Surface tension is very high. Heat capacity is very high. Freezing point of water decreases as pressure increases.

Question 14

Can water dissolve NP molecules?

Answer 14

Permenant bond dipole of water can induce a tempoary bond dipole in a NP molecule.

Magnitude of induced bond dipole depends on size (# of electrons effected) and shape.

Question 15

How is ice less dense than liquid water?

Answer 15

In liquid water, it’s constantly flowing around each other and making/breaking Bond dipoles.

when frozen, it’s rigidly arranged to maximise bond dipoles which causes it to be more open.