Solutions

Question 1

solution

Answer 1

homogeneous mixture
components of a solution are so evenly spread throughout the mixture that there are no perceivable differences in composition

Question 2

solute

Answer 2

substance that is being dissolved

Question 2

solvent

Answer 2

the dissolving medium

Question 3

Unsaturated solutions

Answer 3

solutions in which the amount of dissolved solute is less than the saturation point of the solvent (at that specific temperature gradient)

Question 4

saturated solution

Answer 4

contains the maximum quantity of dissolved solute that is normally possible at a given temperature, where a state of dynamic equilibrium exists between dissolution and crystallization

Question 5

supersaturated solution

Answer 5

more dissolved solute than is normally possible under normal conditions. The solution is unstable and crystallization will occur readily by seeding (introducing particles that provide nuclei for precipitation)

Question 6

molarity (M) of a solution

Answer 6

number of moles of solute dissolved in one litre of solution

Question 7

calculate the molarity of a solution

Answer 7

divide the moles of solute by the volume of the solution expressed in litres

Question 8

concentration

Answer 8

how much of a substance is mixed with another substance

Question 9

dilute a solution

Answer 9

add more solvent
reduce the amount of solute

Question 10

aqueous solution

Answer 10

solvent is water

Question 11

Factors Affecting Solubility

Answer 11

Structural Effects
Temp
Pressure

Question 12

Structure Affect Solubility

Answer 12

solution will form if both solute and solvent have similar molecular structures, polarity and types of interactions
“like dissolves like”

Question 13

Temp Affect Solubility

Answer 13

solids: generally increases as temperature increases
endothermic process (favours high temp)
gases dissolving in liquid solvents: solubility decreases as the temperature increases; the dissolution of gaseous solutes is an exothermic process - when a gas dissolves heat is given off. Gases are more soluble at low temperature than at high temperature.

Question 14

temperature effect on the solubility of gaseous substances environmental implications

Answer 14

as a result of the widespread uses of water from lakes and rivers in the industrial cooling system. The discharged water from the cooling system back into the lakes or rivers is significantly warmer than the natural ambient temperature, which causes thermal pollution. The rise in ambient temperature of lake or river water lowers the concentration of dissolved oxygen, which can be detrimental to the
survival of aquatic lives.

Question 15

Pressure Affect Solubility

Answer 15

little effect on the solubility of solids or liquids, but significantly increases the solubility of gases

Question 16

Electrolytic Dissociation

Answer 16

electrolyte dissolved in water separates into 2 ions of opposite charges
physical charge

Question 17

Degree of dissociation

Answer 17

fraction of a mole of the reactant that underwent dissociation
% dissociation = [HA] dissociated/[HA] initial x 100%
a = C dissociation/C general = N dissociated/ N general
α = amount of substance of the reactant dissociated amount of substance of the reactant present initially. Number of moles dissociated.

Question 18

Strong electrolytes

Answer 18

completely dissociate into ions when dissolved in water
strong acids, strong bases, some salts

Question 19

Weak electrolytes

Answer 19

partially dissociate into ions when dissolved in water
weak acids, weak bases, some salts