EX unit five: solids, liquids and gases

Question 1

density =

Answer 1

mass / volume

Question 2

what is the symbol for density

Answer 2

ρ

Question 3

what is the symbol for volume

Answer 3

V

Question 4

what is density measured in

Answer 4

kg/m cubed or g/cm cubed

Question 5

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

Answer 5

multiply by 1000

Question 6

how do you measure volume (solid)

Answer 6

measure width (w), height (h), and depth (d) and multiply together.

Question 7

how do you measure mass (solid)

Answer 7

use an electronic balance

Question 8

how do you measure mass (liquid)

Answer 8

put a measuring cylinder on the electronic balance, zero it, and pour in the liquid.

Question 9

how do you measure volume (liquid)

Answer 9

pour the liquid in a measuring cylinder. it may be callibrated in ml: 1ml = 1cm cubed.

Question 10

pressure =

Answer 10

force / area

Question 11

whats the symbol for area

Answer 11

A

Question 12

what is pressure measured in

Answer 12

pascals (Pa)

Question 13

what is pressure

Answer 13

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

Question 14

1 Pa =

Answer 14

1 N/m squared

Question 15

pressure difference =

Answer 15

height x density x gravitational field strength

Question 16

what is the symbol for PRESSURE difference

Answer 16

p

Question 17

process of solid to liquid

Answer 17

melting

Question 18

process of liquid to gas

Answer 18

boiling

Question 19

process of gas to liquid

Answer 19

condensation

Question 20

process of liquid to solid

Answer 20

freezing

Question 21

what is a boiling point

Answer 21

when a liquid becomes a gas

Question 22

what is a melting/freezing point

Answer 22

when solid becomes a liquid

Question 23

describe the structure and position of molecules in a solid substance

Answer 23

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 24

describe the structure and position of molecules in a liquid substance

Answer 24

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

Question 25

describe the structure and position of molecules in a gas substance

Answer 25

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

Question 26

what is specific heat capacity

Answer 26

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

Question 27

what is the unit for specific heat capacity

Answer 27

J/kg degrees celsius

Question 28

what is the symbol for specific heat capacity

Answer 28

c

Question 29

heat change =

Answer 29

mass x specific heat capacity x temperature change

Question 30

what is the symbol for heat change

Answer 30

ΔQ

Question 31

what is the symbol for temperature change

Answer 31

ΔT

Question 32

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

Answer 32

pressure acts in all directions at any point

Question 33

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

Answer 33

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

Question 34

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

Answer 34

the average kinetic energy of the gas molecules

Question 35

what is Boyle's law

Answer 35

that volume is inversely proportional to pressure.

Question 36

p1 x V1 =

Answer 36

p2 x V2

Question 37

p1/p2 =

Answer 37

V2/V1

Question 38

what is absolute zero

Answer 38

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).

Question 39

how do you convert celsius to kelvin

Answer 39

add 273

Question 40

how do you convert kelvin to celsius

Answer 40

subtract 273

Question 41

p1/T1 =

Answer 41

p2/T2

Question 42

what does the pressure law mean

Answer 42

if you double the kelvin temperature of gas in a rigid container the pressure of the gas doubles.