Mixtures, Concentrations and pH

Question 1

Mixtures

Answer 1

A combination of elements or compounds that are physically blended together but not bound by chemical bonds

Question 2

Types of liquid mixtures

Answer 2

Solutions
Colloids
Suspensions

Question 3

Solution

Answer 3

A mixture of solute dissolved into a solvent that remains evenly distributed

Question 4

Solvent

Answer 4

A liquid or gas which another substance is dissolved

Question 5

Solute

Answer 5

A substance that is dissolved into a solvent

Question 6

Colloids

Answer 6

A mixtures of solute and a solvent but where the solute particles are large enough to scatter light as it passes through e.g proteins in milk dissolved in water still big enough to scatter light (looks opaque)

Question 7

Suspensions

Answer 7

A mixture in a liquid for a period of time, but eventually it will settle out of the liquid e.g red blood cells and plasma

Question 8

Concerntration

Answer 8

The proportion of solute dissolvent in a solvent

Question 9

Molarity

Answer 9

The number of molecules of solute dissolved in one litre of solvent

Question 10

Acid

Answer 10

A substance that when dissolved in water releases hydrogen ions

Question 11

Strong acid/base tendencies

Answer 11

Dissociate completely to release H+ ions and OH- ions respectively

Question 12

Weak acid/base tendencies

Answer 12

weak tendency to dissociate and release H+ and OH- ions respectively but can also reform

Question 13

Base

Answer 13

A substance when dissolved in water releases hydroxide ions

Question 14

Salt

Answer 14

A substance when dissolved in water releases a cation and an anion neither of which are H+ or OH-

Question 15

Reversible reactions

Answer 15

Are not static, backward and forward reactions are happening continuously. Tend to find a balance (equilibrium) where the forward and back reactions are happening at the same speed

Question 16

Le Chateliers Principle

Answer 16

A change in one of the variables in a system at equilibrium produces a shift in the position of the equilibrium that counteracts the effect of this change

Question 17

pH

Answer 17

Potential hydrogen, A measure of the concentration of hydrogen ions in a solution

Question 18

Characteristics of pH scale

Answer 18

Range = 0-14
7 = neutral
Below 7 = Acidic
Above 7 = Basic
Body pH = 7.4

Question 19

Buffer

Answer 19

A substance that is able to remove or add H+ and it is able to resist large changes in pH e.g weak acids or bases

Question 20

Bodys buffer system

Answer 20

Carbonic acid - bicarbonate buffer system

H^++HCO_3^−⇢⇠H_2 CO_3 ⇢⇠H_2 O+CO_2