Thermal

Question 1

How can the internal energy of an object be increased?

Answer 1

heating it or doing work on it

Question 2

How can the internal energy of an object be decreased?

Answer 2

cooling it or if work is done by it

Question 3

What happens to the temperature of a substance when it changes state?

Answer 3

stays constant

Question 4

Define the specific heat capacity of a substance.

Answer 4

amount of energy needed to raise the temperature of 1 kg of it by 1K (or °C)

Question 5

Give the equation for the specific heat capacity of a substance.

Answer 5

Q＝mc delta theta

Question 6

Give the equation for the energy transferred to a substance if it is heated using an electrical heater.

Answer 6

E= IVt

Question 7

Define the specific latent heat of fusion of a substance.

Answer 7

The he amount of energy needed to change 1kg of solid to liquid without a change in temperatur

Question 8

Give the formula for the energy transferred during a change of state of a substance (with no change in temperature).

Answer 8

Q=m l, where Lis the specific heat of fusion or vaporisation

Question 9

What is absolute zero?

Answer 9

lowest possible temperature (OK or -273.159)

Question 10

Define the Avogadro constant.

Answer 10

6.02 X 1023 - number of atoms in 12g of carbon-12

Question 11

What is the molar mass of a substance?

Answer 11

mass of one mole of that substance

Question 12

How can the molar mass of a compound be calculated?

Answer 12

by adding up the relative atomic masses ofits constituent atoms

Question 13

Give the relationship between the total
number of particles in a sample of a substance and the number of moles.

Answer 13

N=n X NA

Question 14

What does Boyle’s law state?

Answer 14

for a fixed mass of gas at constant temperatures pressure and volume are inversely proportional

Question 15

What does Charles’ law state?

Answer 15

for a fixed mass of gas at constant pressure the volume and absolute temperature are directly proportional

Question 16

What does the pressure law state?

Answer 16

for a fixed mass of gas at constant volume the pressure and absolute temperature are directly proportional

Question 17

Give the equation for the energy transferred to increase or decrease the volume of a gas at a constant pressure.

Answer 17

W= p delta V

Question 18

Define an ideal gas.

Answer 18

theoretical gas which obeys the experimental gas laws at all pressures and temperatures

Question 19

Give the two ideal gas equations

Answer 19

p V=n RTand pV=NkT

Question 20

Give the kinetic theory equation.

Answer 20

pV = 1/3Nm (Crms)^2