Thermal

Question 1

Internal Energy

Answer 1

The internal energy of a body is the sum of the randomly distributed kinetic and potential energies of all its molecules.

Question 2

Specific Latent heat of fusion or vaporisation

Answer 2

The specific latent heat of fusion or vaporisation is the quantity of thermal energy required to change the state of 1kg of a substance without a change in temperature

Question 3

The internal energy of an object is increased because…

Answer 3

Energy transfer by heating or work is done on the object (e.g by electricity)

Question 4

The internal energy of an object stays constant when

Answer 4

No energy transfer is done on the object, energy transfer by heating and work done balance each other out.

Question 5

The inversion tube experiment (what is it and the equation)

Answer 5

Lead spheres inside a tube, are inverted and spheres hit the bottom of the tube. The temperature is measured after n inversions.

c =gLn/T
c is the specific capacity of lead, g is gravity, L is the length of the tube, n is the number of inversions and T is the temperature change

Question 6

the change of internal energy of the object =

Answer 6

the total energy transfer due to work done and heating

Question 7

If a solid has a larger specific heat capacity than the liquid

Answer 7

the liquid heats up faster than the solid

Question 8

The rise in temperature per second (T/t)

Answer 8

= P/mc

Question 9

When a change of state occurs, what energy changes occurs

Answer 9

Kinetic energy stays the same, but potential energy increases as bonds are broken

Question 10

Boyles Law

Answer 10

PV = constant

Question 11

Charles law

Answer 11

V/T = constant

Question 12

Pressure law

Answer 12

p/T = constant

Question 13

Brownian motion

Answer 13

The erratic random movement of microscopic particles in a fluid, as a result of continuous bombardment from molecules of the surrounding medium

Question 14

What does Brownian motion show

Answer 14

the existence of molecules and atoms

Question 15

Ideal gas

Answer 15

An ideal gas strictly obeys the equation of state

pV = nRT, (give some conditions of an ideal gas)

Question 16

Heat is the

Answer 16

energy flow from a region at a higher temperature to a region at a lower temperature, due to the temperature difference

Question 17

In an ideal gas, molecules of the gas are

Answer 17

identical

Question 18

In an ideal gas, molecules exert no forces on each other except

Answer 18

during impact

Question 19

In an ideal gas, the motion of molecules is

Answer 19

random

Question 20

In an ideal gas, the time during collisions is

Answer 20

negligible compared to the time between collisions

Question 21

In an ideal gas, what laws of physics are applied

Answer 21

Newtonian laws of physics

Question 22

In an ideal gas, there is a large number

Answer 22

of particles

Question 23

In an ideal gas, collisions are

Answer 23

elastic

Question 24

The specific heat capacity of a substance is

Answer 24

the energy needed to raise the temperature of unit mass of the substance by 1k without change of state.

Question 25

What are the two equations for moles calculations

Answer 25

N = n X Na

mass (in grams) = Mr x Moles