states of matter

Question 1

there are 3 states of matter. what are they?

Answer 1

1. solid
2. liquid
3. gaseous

Question 2

what are the particulate theory of matter

Answer 2

1. all matter is composed of particles
2. the particles are in constant motion and temperature affects their speed of motion
3. the particles have empty spaces between them
4. the particles have forces of attraction between them

Question 3

what is diffusion

Answer 3

diffusion is the net movement of particles from a region of higher concentration to a region of lower concentration, until the particles are evenly distributed

Question 4

what are some examples of diffusion

Answer 4

cotton wool and hcl

Question 5

explain this lab

Answer 5

pieces of wool are soaked in ammonia solution and conc hcl is placed simultaneously on opposite ends of the glass tube. a white ring of ammonium chloride forms inside.

Question 6

chemistry behind ammonia and hcl

Answer 6

ammonia particles diffuse faster than hydrogen chloride particles, so there they collide and form at the side of hcl ( where it was slower)

Question 7

another example of diffusion

Answer 7

potassium manganate crystals

Question 8

what happens here when kmno crystals are placed in water?

Answer 8

when kmno crystals are placed in water, it dissolves to produce a uniformly purple solution. the particles that makes up the crytals diffuse through the spaces within the water until they are evenly distributed.

Question 9

what is osmosis

Answer 9

osmosis is the movement if water molecules through a differentially permeable membrane from a solution containing a lot of water molecules.

Question 10

what are some examples of osmosis

Answer 10

when a strip of paw paw was placed in water, water molecules move into the cells by osmosis. each cell swells slightly therefore the strip increases in length and becomes rigid.

Question 11

another explanation follows when pawpaw strips are placed in water

Answer 11

when the strip is placed in a conc solution of NaCl solution, water molecules move out of the cells by osmosis. each cells shrink therefore decreases in length and becomes softer.

Question 12

uses of osmosis

Answer 12

1. to control garden pests

2. to preserve food

Question 13

explain the first use of osmosis- to control garden pests

Answer 13

pests that have permeable skin and is always moist, salt can dissolve in the moisture around their bodies forming a conc solution. water inside their bodies move out by osmosis and into the solution they then die from dehydration

Question 14

explain the second use of osmosis- to preserve food

Answer 14

salt and sugar are used to preserve foods eg meat, fish and fruits. they draw water out of the cells of the food by osmosis. this prevents the food from decaying bc there is no water available in the cells for chemical reactions to occur

Question 15

another explanation

Answer 15

they draw water out of microorganisms by osmosis. this prevents the food from decaying bc it inhibits the growth of microorganisms.

Question 16

types of particles that make up matter are

Answer 16

1. atoms
2. molecules
3. ions

Question 17

explain the properties of solid, liquid and gas in their states

Answer 17

solid- fixed shape and volume, high density, difficult to compress, packed closely-usualy tgt, strong force of attraction, posses small amt of kinetic energy, vibrate in their fixed positions

Question 18

describe liquid in its states

Answer 18

takes shape of container, fixed volume, denisty is lower than solids, can be compressed by applying pressure, have small spaces btween them and are randomly arranged, weaker than those between the particles in solid, posses more kinetic energy, move slowly pass eachother,

Question 19

explain gas

Answer 19

takes the shape of the entire container, variable density- expands to fill container, low density, very easy to compress, have large spaces between them and are randomly arranged, very weak force of attraction, posses large amt of kinetic energy, ,move around freely and rapidly.

Question 20

changing state of solid

Answer 20

when it is heated, it changes from liquid to gas. this happens bc the particle gain kinetic energy, move increasingly faster and further apart, and the forces of attraction becomes weaker.

Question 21

what happens to gas

Answer 21

when a gas is cooled, it changes from liquid to solid. this occurs bc the particles lose energy, move more slowly and closer tgt, and the forces of attraction becomes stronger.

Question 22

what is a heating curve

Answer 22

a heating curve is drawn when the temperature of a solid is measure at intervals as it is heated and changes states to a liquid and then to a gas.
temperature is plotted against time

Question 23

what is a cooling curve

Answer 23

this is when the temp of a gas is measured at intervals when it is cooled and changes state to a liquid. the temp is plotted against time

Question 24

what is the melting point

Answer 24

this is the constant temperature at which a solid changes into a liquid

Question 25

what is the boiling point

Answer 25

this is the constant temp at which a liquid changes into gas

Question 26

what is the freezing point

Answer 26

this is the constant temperature at which a liquid changes into a solid