Chap 5

Question 1

whats the density of water

Answer 1

1 g cm3

Question 2

does water have a high surface tension or low surface tension

Answer 2

high

Question 3

what is surface tension

Answer 3

a result of cohesive force betweeen the molecules of water at the surface that allows various things to float to water

Question 4

meaning of capillary action

Answer 4

cohesive force between water molecules n adhesive force between water molecules and cell walls of xylem which allow water to be drawn up from the roots to leaves.

Question 5

what results in the change of water?

Answer 5

absorption and release of heat

Question 6

water is a compound made out from :

Answer 6

hydrogen and oxygen that combine chemically

Question 7

how can we determine the composition elements in a water molecule

Answer 7

through electrolysis

Question 8

during electrolysis , oxygen gas is produced at the _______ while hydrogen gas is produced at the ___________

Answer 8

anode, cathode

Question 9

whats an anode

Answer 9

the electrode that is connected to the positive terminal of a battery

Question 10

whats a cathode

Answer 10

the electrode that is connected to the negative terminal of a battery

Question 11

what is salt’s effect on ice and water

Answer 11

• lowers melting point of ice
• increases boiling point of water

Question 12

What is evaporation

Answer 12

the process that happens at the surface of water that changes water to water vapour

Question 13

what are the 4 factors that affect the rate of evaporation of water

Answer 13

humidity, surrounding temp, exposed surface area of water, movement of air

Question 14

how does humidity affect the rate of evaporation of water

Answer 14

• dry air contains less water vapour and therefore can hold more water molecules that escape from the surface of water

Question 15

how does surrounding temp affect the rate of evaporation of water

Answer 15

• when surrounding temp increase, the water molecules at the surface gain more energy, move faster n escape into the air easily.

Question 16

how does exposed surface area of water affect the rate of evaporation of water

Answer 16

exposed surface area that is larger allows more water molecules to escape

Question 17

how does movement of air affect the rate of evaporation of water

Answer 17

-sweeps away water vapour in the air
- high speeds of wind cause the air at the surface of water to dry

Question 18

whats a solute

Answer 18

substance that can dissolve in a liquid

Question 19

whats a solvent

Answer 19

liquid that dissolves a substance

Question 20

whats a solution

Answer 20

mixture formed when a solute dissolves in a solvent

Question 21

Solutions formed can be classified as: (3)

Answer 21

dilute solution, concentrated solution and saturated solution

Question 22

Characteristics of Dilute solution

Answer 22

-less amount of solute in the solvent
- can dissolve more solute

Question 23

Characteristics of concentrated solution

Answer 23

-more amount of solute in the solvent
-can dissolve less solute

Question 24

characteristics of saturated solution

Answer 24

-excess amount of solute in the solvent
- cannot dissolve any more solute and form precipitate

Question 25

difference between solution n suspension

Answer 25

solution is a clear mixture formed when a solute dissolves in a solvent suspension is a cloudy mixture formed from undissolved solute particles in a solvent

Question 26

What is Solubility

Answer 26

Solubility of a solute is the maximum amount of the solute that can dissolve in the solvent at a specific temp

Question 27

what affects the rate of solubility

Answer 27

high temperature, rate of stirring and size of solute

Question 28

why does the size of solute affect the rate of solubility

Answer 28

the smaller the size of solute, the bigger the total surface area that is exposed to the solvent particles

Question 29

whats a colloid

Answer 29

a mixture of two or more solutes dispersed evenly in a solvent, it is an intermediate between a solution and a suspension

Question 30

why is water known as a universal solvent

Answer 30

due to its ability to dissolve almost all substances, solids,liquids or gases

Question 31

What are the 5 categories of organic solvents

Answer 31

alcohol kerosene acetone turpentine ether

Question 32

whats the use of organic solvents

Answer 32

can be used to dissolve solutes that are insoluble in water

Question 33

what r the 4 water purification methods

Answer 33

boiling, chlorination, filtration, distillation