Chapter 2

Question 1

What is an ideal gas

Answer 1

an ideal gas obeys simple laws such as charles, boyles, dalton and amagats law

Question 2

Is there any gas that exists that obeys ideal laws

Answer 2

there are no gases which obey these laws over a complete range of pressures and temperature

Question 3

What is the ideal gas equation

Answer 3

PV = nRT
P - total pressure
V - total volume
n - no. of mols
R- universal gas constant ( 8.314)
T - temperature

Question 4

What is the difference between ideal and non - ideal gases

Answer 4

ideal gases are lighter gases ( H2, O2, N2) whilst non ideal gases are heavier gases ( SO2. CO)

Question 5

When do problems arise for ideal gas behaviour

Answer 5

1. when the vapour is near the boling point at the liquid
2. when you have a high pressure system

Question 6

how do you work out specific volume

Answer 6

specific volume = Volume / moles

Question 7

What is STP

Answer 7

Standard temperature and Pressure

temp - 273.15 Kelvin
Pressure - 1 atm / 10^5 Pa

Question 8

What is ntp

Answer 8

Normal temperature (20 degrees C) and Pressure
(1 atm)

used in engineering applications

Question 9

molar gas density equation

Answer 9

molar gas density = moles / volume
or
molar gas denisty = pressure / RT

Question 10

What is density proportional to

Answer 10

Pressure

Question 11

What is density inversely proportion to

Answer 11

Temperature

Question 12

What is Dalton Law of partial pressure

Answer 12

There is Fixed Volume and Fixed Temperature

Total pressure of ideal gas is equal to the sum of pressure exerted by individual components. Each component gas exerts a partial pressure which is the pressure obtained if the same mass of individiual gas were alone in the same total volume and temperature as the gas mixture

Question 13

What is Amagats law of additive volume

Answer 13

There is fixed Temperature and Fixed Pressure

The total volume of the ideal gas mixture equals the sum of the individual gas volumes as if they were measured at the same Temp and Pressure as the whole mixture. The individual volumes are known as partial volume

Question 14

Dalton law equaton for partial pressure

Answer 14

The partial pressure of a component in an ideal gas mixture equals the product of the mole fraction of component and total pressure

Pi = Yi x Pt

Pi = partial pressure of component
Yi = mol fraction of component
Pt - total pressure

Question 15

What is Pa /Pt equal to

Answer 15

Via dalton law we can ssay :

Pressure of Component/ Total pressure = Mol of component / Total mol

Question 16

Amagat law equation of additive volume

Answer 16

Volume fraction of A = Mole fraction of A

The volume fraction of an ideal gas is equal to the mol fraction of that ideal gas

Question 17

What is Va/ Vt equal to

Answer 17

Via amagats law we can say:

Va/ Vt = Na / Nt

Question 18

What relationships are non ideal

Answer 18

Van der waal equations
Holborn
Soave- redlich kwong

Question 19

What is a vapour

Answer 19

Vapour is a gas phase component which can be liquified by isothermal compressions

Question 20

What is a gas

Answer 20

Gas is a phase component which cannot be liquefied by isothermal compressions

Question 21

Which gases cannot be condensed even up to pressures of 5000 atm

Answer 21

Oxygen and nitrogen

Question 22

What does phase diagram describe

Answer 22

It describes the relationship between vapour, liquid, gases and solid as a function of pressure and temperature

Question 23

What is equilibrium in phase diagrams

Answer 23

Equilibrium is a state with no tendency towards spontaneous change

Question 24

What is the triple point on phase diagram

Answer 24

The triple point is when all 3 phases (solid, liquid, vapour) exist in equilibrium

Question 25

What is called when vapour turns into a solid

Answer 25

Condensation

Question 26

What is called when solid turns into a vapour

Answer 26

Sublimation

Question 27

What is called when solid turns into a liquid

Answer 27

melting

Question 28

What is called when liquid turns into a solid

Answer 28

Freezing

Question 29

What is called when liquid turns into a vapour

Answer 29

vapourisation

Question 30

What is called when vapour turns into liquid

Answer 30

condensation

Question 31

What is the critical point

Answer 31

Above critical temp and critical pressure, liquid and gas phases co exist and have same density

Question 32

What are examples of equilibrium processes

Answer 32

Vapourisation and condensation at constant Temp and Pressure

Question 33

What is the equilibrium process known as

Answer 33

Saturated vapour pressure

Question 34

What happens at any given Temperature in equilibrium

Answer 34

At any given Temp, theres only one pressure where both liquid and vapour phases can exist in equilibrium

Question 35

What is sensible heat

Answer 35

Sensible heat is when adding heat causes temperature change but no phase change

Question 36

What is latent heat

Answer 36

temperature remains fixed, as we apply more heat to component

Question 37

What is latent heat units

Answer 37

Energy per unit mass,

it is Temperature and Pressure dependent

Question 38

What is the latent heat at the critical point

Answer 38

Zero as at critical point no energy is required to convert the phases

Question 39

What is Raoult’s law

Answer 39

At equilibrium for an ideal mixture, the partial pressure of a vapour phase component equals to the SVP of that component multiplied by the mole fraction of the component in the liquid phase

Question 40

What is the equation for Raoults law

Answer 40

Vapour pressure = Mol Fraction of solvent x Standard Vapour Pressure

Question 41

What happens when you put a non volatile solute into pure solvent

Answer 41

You decrease the vapour pressure, meaning it doesnt evaporate off the surface as the surface is now crowded so it is harder to escape.