unit five: solids, liquids and gases

Question 1

order solids, liquids and gases in order of density from high to low

Answer 1

solids, liquids, gases

Question 2

density =

ρ =

Answer 2

mass / volume

m/V

Question 3

what can density be measured ijn

Answer 3

kg/mcubed or g/cmcubed

Question 4

what do you use to measure a regular solid

Answer 4

a half-metre rule

Question 5

how do you measure the volume of a liquid displaced by an irregular solid

Answer 5

make sure the measuring cylinder is on a flat surface and you look at the scale straight on to avoid parallax error

Question 6

how do you measure the volume of an irregular soid

Answer 6

measure mass using weighing scales, put in a displacement can and measure the volume of liquid displaced.

Question 7

pressure =

p =

Answer 7

force / area

F/A

Question 8

what is pressure measured in

Answer 8

pascals

Question 9

what is force measured in

Answer 9

newtons

Question 10

what is area measured in

Answer 10

square metres.

Question 11

why does a stiletto or pin have more ability than your thumb

Answer 11

all the pressure is concentrated on one point

Question 12

pressure in liquids act…

Answer 12

equally in all directions (as long as it isn’t moving)

Question 13

what is the pressure exerted on humans by the atmosphere

Answer 13

about 100 000 Pa

Question 14

pressure difference =

Answer 14

height x density x gravitational field strength

h x ρ x g

Question 15

how do you convert from g/cm cubed to kg/m cubed

Answer 15

multiply by 1000

Question 16

what is pressure

Answer 16

weight in newtons per metre squared acting down on a surface.

Question 17

1 Pa =

Answer 17

1 N/m squared

Question 18

solid to liquid

Answer 18

melting

Question 19

liquid to gas

Answer 19

boiling

Question 20

gas to liquid

Answer 20

condensation

Question 21

liquid to solid

Answer 21

freezing

Question 22

what is a boiling point

Answer 22

when a liquid becomes a gas

Question 23

what is a melting or freezing point

Answer 23

when a solid becomes a liquid

Question 24

describe the structure and position of molecules in a solid substance

Answer 24

the molecules in a solid are tightly packed and held in fixed positions by strong forces. the molecules can vibrate around their fixed positions. as the solid gets hotter the vibrations get bigger.

Question 25

describe the structure and position of molecules in a liquid substance

Answer 25

closely packed
irregular structure
intermolecular forces are strong molecules move randomly.

Question 26

describe the structure and position of molecules in a gas substance

Answer 26

widely spaced
continuous state of random motion
weak intermolecular forces except during collisions
molecules move randomly.

Question 27

particles in a solid:

Answer 27

tightly packed
held in fixed pattern or crystal structure by strong forces
vibrate around their fixed positions

Question 28

particles in a liquid:

Answer 28

tightly packed
are not held in fixed positions but are still bound together by strong forces
move at random with no fixed positions

Question 29

particles in a gas:

Answer 29

are very spread out
have no fixed positions and the forces between them are very weak
move in a rapid random motion

Question 30

what is specific heat capacity

Answer 30

the amount of energy required to increase the temperature of 1 kilogram of a certain substance by 1 degree celsius.

Question 31

what is the unit for specific heat capacity

Answer 31

J/kg degrees celsius

Question 32

what is the symbol for specific heat capacity

Answer 32

c

Question 33

heat change =

Answer 33

mass x specific heat capacity x temperature change

Question 34

what is the symbol for heat change

Answer 34

ΔQ

Question 35

what is the symbol for temperature change

Answer 35

ΔT

Question 36

1st gas law: the random motion of gas and liquid particles explains why…

Answer 36

pressure acts in all directions at any point

Question 37

2nd gas law: the speed of molecules increases with temperature, so as we heat gases in a rigid container, more.

Answer 37

energetic collisions with the walls happen more frequently, raising the pressure of the gas.

Question 38

3rd gas law: the temperature of a gas in Kelvin is proportional to…

Answer 38

the average kinetic energy of the gas molecules

Question 39

what is Boyle’s law

Answer 39

that volume is inversely proportional to pressure.

Question 40

p1 x V1 =

Answer 40

p2 x V2

Question 41

p1/p2 =

Answer 41

V2/V1

Question 42

what is absolute zero

Answer 42

when you cool a fixed mass of gas at constant volume, its pressure drops. if you continue to cool the gas below 0 degrees celsius, the pressure will keep dropping until the pressure is zero, and graphs predict that this will happen when the temperature is -273 degrees celsius, and this is the lowest possible temperature. this is called 0 Kelvin (K).