Solutions

Question 1

What does slightly soluble mean

Answer 1

low temps it doesn’t dissolve but at higher temps it dissolves a little

Question 2

Unsaturated solution

Answer 2

More solute can be added and it will still dissolve

Question 3

Saturated solution

Answer 3

when no more solute can dissolve, solvent and solute are in equal amounts, if more solute is added a solid precipitate will form

Question 4

Supersaturated solution

Answer 4

increasing the temp or pressure which then allows more solute to dissolve, then decreasing the temp it becomes supersaturated

Question 5

Solubility

Answer 5

Measured as grams of solute per 100g of solvent

Question 6

Solubility affecting factors when a solid solute is added

Answer 6

Increasing temp, increases solubility (several exceptions) as average kinetic energy increases meaning particles have enough energy to overcome the forces of attraction in the solute and solvent allowing new interactions to occur, Decreasing particle size, increases solubility
Increasing stirring (speeding up particles), increases solubility

Question 7

Solubility affecting factors in a gas solute

Answer 7

Increasing temp, decreases solubility as this increases the average kinetic energy which allows the molecules to break the intermolecular bonds escaping from the liquid, Increasing pressure, increases solubility

Question 8

What must happen for a solution to form

Answer 8

Solute interaction forces need to be overcome for it to dissolve, Solvent interaction forces need to be overcome to make space for solute particles, New interactions must have greater or equal strength than that of solute-solute of solvent-solvent interactions

Question 9

What do the particles have to do to form new interactions with greater energy

Answer 9

Particles must have correct orientation which occurs through Brownian motion (the erratic and random movement of molecules)

Question 10

When does an ion-dipole interaction occur

Answer 10

When an ionic compound dissolves in water

Question 11

What is an example of an ion-dipole interaction

Answer 11

When NaCl is dissolved in water the ion-dipole attractions between Na ions and Cl ions and the water molecules are strong enough to pull the ions from their positions in the crystal lattice

Question 12

Hydration

Answer 12

When the water molecules surround the ions in a solution

Question 13

What polar covalent molecules will ionise

Answer 13

Highly polar compounds will form ions when dissolved in water as the covalent bonds break when the compound is placed in water as a result of the electrostatic force of attraction between the solute molecules and water molecules

Question 14

Polar covalent molecules that don’t ionise

Answer 14

Some polar covalent molecules don’t break down into ions and instead dissolves the attraction between the polar covalent molecules and polar water molecules which causes the covalent crystal structure to break up