states of matter ( checklist)

Question 1

when a solid is heated, what happens ( particles and state)

Answer 1

• particles gain more kinetic energy
• this makes the particles vibrate more, weakening the forces holding the solid together
• at a certain temp. the particles break free from their bonds (melting)

this temperature is called the melting point

it has then melted so become a liquid

Question 2

when a liquid is heated, what happens (particles and state)

Answer 2

• particles get even more kinetic energy
• this energy makes the particles move faster, weakening the bonds holding it together
• At the boiling temperature, particles separate from the bonds and the liquid turns into a gas

Question 3

when a substance changes state, does its temperature change ?

Answer 3

no

Question 4

why does a substance not change temperature when changing state ? (heating)

Answer 4

because the energy you are putting in is being used to overcome the forces of attraction between the particles rather than speed up the movement

Question 5

why does a substance not change temperature when changing state ? (cooling)

Answer 5

when you cool a substance, then energy being released is coming from the formation of new forces and is not being released from the slowing down of particles so temp stays the same.

Question 6

in a cooling curve, will the line travel from top to bottom or bottom to top

Answer 6

top to bottom

Question 7

in heating and cooling curves, what do the flat bits mean

Answer 7

they’re when the substance is changing state

Question 8

what do the 45º lines man in heating & cooling curves

Answer 8

temperature of substance are changing

Question 9

increasing the pressure of a gas will ____ its volume

why

the particles in a gas are far apart, if you increase the pressure you are pushing them closer together so volume decreases

Answer 9

decrease

Question 10

increasing the temperature of a gas will ____ its volume

why

Answer 10

increase

if you heat a gas, the particles move faster and gain more kinetic energy. because they are faster and have more energy they will travel further, increasing the volume.

Question 11

gas to liquid

Answer 11

condensing

Question 12

liquid to gas

Answer 12

evaporating

Question 13

liquid to solid

Answer 13

freezing

Question 14

solid to liquid

Answer 14

melting

Question 15

gas to solid

Answer 15

sublimation

Question 16

what is diffusion

Answer 16

when a substance changes from an area of high concentration to an area of low concentration

Question 17

dilution experiments support a theory that ?

Answer 17

all matter, solids, liquids and gases is made up of tiny moving particles

Question 18

diffusion of gases experiment /explanation

Answer 18

in the beginning, all the bromine molecules are trapped in the bottom half of container (thin piece of plastic holding it)
since there are a lot of bromine molecules close together, the colour is darker
the upper half contains no bromine but contains atmospheric gases
when you remove the piece of plastic, bromine molecules will move up through the container ( through diffusion)
the particles move randomly, but over time will spread out evenly across container
now the bromine particles are much further apart, and so the colour is much paler

Question 19

what is a solvent

Answer 19

the liquid in which a solute is dissolved

Question 20

what is a solute

Answer 20

solid that is dissolved in the solvent

Question 21

what is a solution

Answer 21

mixture of solute and solvent

Question 22

what is a saturated solution

Answer 22

A solution that is so full of solute that no more solute can dissolve in it

Question 23

dilution of solids experiment /explanation

Answer 23

potassium manganate crystals (solute) get dissolved in water (solvent) which forms a dark purple solution

• the potassium manganate molecules move randomly in the solution and are evenly spread

the more water you add, the lighter the colour becomes

• it becomes more dilute as there is less solute, and more solvent in the solution

Question 24

If 10 g is the maximum amount of solute that dissolves in 100 ml solvent before it becomes saturated, then its solubility is

Answer 24

in 100 ml solvent before it becomes saturated, then its solubility is 10

Question 25

if you only have 50ml of solvent ( in solubility in g/100g solvent) an 10g is the maximum amount of solute, what is the solubility

Answer 25

20g/ 100ml

double if you only have 50ml, you need 100ml

Question 26

a solubility curve is a graph that represents

Answer 26

the solubility of a solute at different temperatures

Question 27

units for solubility

Answer 27

g/100ml

Question 28

PRACTICAL INVESTIGATE SOLUBILITY OF A SOLID IN WATER AT A SPECIFIC TEMPERATURE

Answer 28

1. Set water bath to a specific temperature (choose something reasonable)
2. Measure out specific volume of water (100ml for ease)
3. Place beaker containing water in the water bath. Monitor temperature until it has reached the temperature of the water bath
4. Add a known mass of solid and stir until is has dissolved
5. Repeat until no more dissolves
6. Note down how much solid dissolved*