5. Solids, liquids, gases

Question 1

density equation

Answer 1

density = mass / volume

Question 2

pressure equation

Answer 2

pressure = force / area

Question 3

what does pressure in a gas or liquid at rest do

Answer 3

act equally in all direction

Question 4

pressure difference equation

Answer 4

pressure difference = height (depth) x density x gravitational field strength

Question 5

PAPER 2

explain why heating a system will change the energy stored within the system and raise its temperature

Answer 5

???

Condensing / freezing

Bonds forming between particles
= energy released

Temp doesn’t go down until all substance has changed state

Question 6

PAPER 2

explain why heating a system will change the energy stored within the system and produce changes of state

Answer 6

???

Melting / boiling

Energy used for breaking intermolecular bonds ( rather than raising temp )

Substance stays at constant temp

Question 7

PAPER 2

Describe changes of state in melting ( solid to liquid )

Answer 7

heat energy= particles vibrate faster= forces between them are overcome

Question 8

PAPER 2

Describe changes of state in boiling ( liquid to gas )

Answer 8

heat energy = particles move faster = increase in energy= overcome attraction between particles

Question 9

PAPER 2

describe particles in a solid

Answer 9

Strong intermolecular forces of attraction

Vibrate around fixed position

Small distances between them ( close together )

Question 10

PAPER 2

describe particles in a liquid

Answer 10

Weak intermolecular forces of attraction

Free to move around within the confines of the liquid

Move in random directions at low speeds

Close together but move past each other = irregular arrangements

Question 11

PAPER 2

describe particles in a gas

Answer 11

Very weak/non-existent forces of attraction (bonds)

free to move around the container (random directions)

fast speeds ( high energy )

large distances between them.

Question 12

PAPER 2

definition of specific heat capacity

Answer 12

the energy required to change the temperature of an object by one degree Celsius per kilogram of mass (J/kg*C)

Question 13

PAPER 2

change in thermal energy equation ( specific heat capacity )

Answer 13

change in thermal energy = mass x specific heat capacity x change in temperature

Question 14

explain the molecules in gas

Answer 14

random motion = constantly colliding = exert a force =pressure on walls of a container

Question 15

what is absolute zero

Answer 15

-273*C
start of the Kelvin scale
coldest anything can get
atoms have as little kinetic energy as its possible to ger

Question 16

how do u convert

1. degrees C to kelvin
2. kelvin to degrees C

Answer 16

1. • 273

2. - 273

Question 17

what happens to gas molecules when you increase the temperature

Answer 17

increase average kinetic energy = particles vibrate faster = forces overcome = particles start to move around

Question 18

if you double the temperature ( in kelvin) what happens to the average kinetic energy of the particles

Answer 18

it doubles

Question 19

what is the rule of the temp ( in kelvin) and the av. kinetic energy of particles

Answer 19

the temp of a gas ( in kelvins) is proportional to the average kinetic energy of its particles

Question 20

what is the equation for a fixed mass of gas at a constant temp.

Answer 20

pressure x volume = constant

Question 21

equation ( short hand ) for gas at constant temp.

Answer 21

p1V1=p2V2

Question 22

what is the equation for a fixed mass of gas at a constant volume

Answer 22

pressure / temp (in kelvin) = constant

Question 23

equation ( short hand ) for gas at constant volume

Answer 23

p1 / T1 = p2 / T2