P1 1a states of matter

Question 1

what are the particles in a solid like?

Answer 1

closely packed in a regular arrangement, no gaps between them
- only movement is vibration

Question 2

do solids have strong or weak forces of attraction?

Answer 2

strong forces of attraction

Question 3

what are the particles in a liquid like?

Answer 3

still close together with minimal gaps, random arrangement

- the particles can move freely but they stay touching

Question 4

do liquids have strong or weak forces of attraction?

Answer 4

not as strong as solids because they are able to move

Question 5

what are the particles in a gas like?

Answer 5

gas particles move wherever as they are separated, random arrangement
- absolute free movement

Question 6

do gases have strong or weak forces of attraction?

Answer 6

no forces of attraction

Question 7

what happens if you heat a solid?

Answer 7

a solid will melt into a liquid
- energy makes the particles vibrate more and more, eventually the forces of attraction aren’t strong enough to hold the particles together

Question 8

what happens if you cool a liquid?

Answer 8

it will freeze and become a solid

- particles move more slowly as they loose energy and the forces of attraction will strengthen making it become a solid

Question 9

what happens if you heat a liquid?

Answer 9

it boils or evaporates into a gaseous state

- the particles gain energy from the heat and move fast enough to completely break forces of attraction

Question 10

what happens if you cool a gas?

Answer 10

it condenses, of turns back into a liquid
- particles will lose heat energy and therefore move slow enough for forces of attraction to hold them together as a liquid

Question 11

what is a melting point?

Answer 11

the temp in which a solid turns into a liquid

Question 12

what is a boiling point?

Answer 12

the temp that turns a liquid into a gas

Question 13

what is a freezing point?

Answer 13

the temp where the liquid turns into a solid

Question 14

what is sublimation?

Answer 14

when a solid becomes a gas straight away

Question 15

what is diffusion?

Answer 15

it is the spreading of gases in the air

• air and bromine gas move randomly and there are large gaps between that allow for mixing
• for example a smell from one side of the room will diffuse to the other but it will take some time

Question 16

what is the difference between evaporation and boiling?

Answer 16

evaporation only occurs at the surface of the liquid, and the gas particles will cool
- boiling is fast, produces lots of bubbles

Question 17

how fast can diffusion happen?

Answer 17

lighter particles are faster, bigger ones are slower

Question 18

what is diffusion in liquids?

Answer 18

when particles diffuse they do so from a region of high concentration to a region of low concentration

Question 19

what happens to the concentration of a liquid when diffusion occurs?

Answer 19

• at the start and around the thing that is being diffused it has a very high concentration
• concentration will decrease the longer the particles are left to evenly spread
• after hours an equilibrium is reached

Question 20

why is diffusion in liquids slower?

Answer 20

the particles in a liquid are closely packed together and move more slowly

Question 21

what is dilution?

Answer 21

it is the addition of a solvent, which decreases the concentration of the solute in the solution
- when something is diluted and the colour does not fade there must be lots of particles in a small amount of the element (particles will be small)

Question 22

what is a solute?

Answer 22

the substance which dissolves in a liquid to form a solution

- salt in sea water

Question 23

what is a solvent?

Answer 23

the liquid in which a solute dissolves

- water in sea water

Question 24

what is concentration?

Answer 24

the amount of solute and how much there is in the solvent, gets weaker as more solvent is added

Question 25

what is a solution?

Answer 25

the mixture formed when a solute is dissolves in a solvent

- seawater

Question 26

what is a saturated solution?

Answer 26

a solution with the maximum concentration of solute dissolved in the solvent
- seawater in the Dead Sea

Question 27

what is meant by soluble?

Answer 27

a substance that will dissolve

Question 28

what is meant by insoluble?

Answer 28

a substance that will not dissolve

Question 29

what is solubility?

Answer 29

a measurement of how much of a substance will dissolve in a given volume of liquid

Question 30

how is solubility expressed?

Answer 30

in g/100g of solvent

Question 31

what effects solubility?

Answer 31

as temperature increases 
- solids become more soluble
- gases become less
as pressure increases 
- gases become more soluble

Question 32

if 10g is the maximum amount of solute that dissolves in 100ml of solvent (before it gets saturated) what is the solubility?

Answer 32

10g/100ml

Question 33

if 10g is the maximum amount of solute that dissolves in 50ml of solvent (before it gets saturated) what is the solubility?

Answer 33

20g/100ml

Question 34

how do you figure out the solubility of a solid in water at a specific temperature?

Answer 34

1. set water bath to the specific temperature
2. measure a specific volume of water using measuring cylinder and put in a beaker (100ml)
3. place beaker in water bath, and monitor the temp until it reaches the specific temp
4. add known mass of solid and stir until dissolved
5. keep adding known masses (small bits at a time) until no more solid dissolves, then note the amount dissolved

Question 35

do protons have a positive or negative charge?

Answer 35

positive, relative mass of 1, +1 charge

Question 36

do neutrons have a positive or negative charge?

Answer 36

neutral charge, relative mass of 1

Question 37

do electrons have a positive or negative charge?

Answer 37

negative, -1 charge

Question 38

what happens when there are different numbers so protons and electrons (lose or gain electrons) ?

Answer 38

the atom would become an ion