Developing Fuels

Question 1

What is the ideal gas equation?

Answer 1

pV =nRT

Question 2

What are the standard conditions?

Answer 2

298K

1 atm

Question 3

Is bond breaking exo or endo thermic?

Answer 3

Endo

Question 4

Is making bonds endo or exo thermic?

Answer 4

Exo thermic

Question 5

What is the mechanism of a heterogeneous catalyst?

Answer 5

Reactants adsorb to surface

Bonds are strained and broken

Bonds reform to make products

Product desorb away

Question 6

What does a catalyst poison do?

Answer 6

Poisons adsorb to surface of catalyst more strongly than reactants so they don’t have a catalyst surface

Question 7

What are the reaction conditions needed for cracking?

Answer 7

Hydrocarbon vapour over a heated catalyst

Question 8

What does aliphatic mean?

Answer 8

There is no benzene ring

Question 9

What does aromatic/ arene mean?

Answer 9

There is a benzene ring

Question 10

What is a homologous series?

Answer 10

A group of compounds with the same functional group

Question 11

What does incomplete combustion form?

Answer 11

Carbon monoxide, unburnt hydrocarbons and particulates

Question 12

What is the test for saturation?

Answer 12

Bromine water

Question 13

What catalyst is needed in the electrophillic addition of hydrogen to a Allene?

Answer 13

Nickel catalyst, heat and pressure

Or

Platinum catalyst with RTP

Question 14

Define structural isomer,

Answer 14

Same molecular formula, different structural formula

Question 15

What is a stereoisomers?

Answer 15

Same structural formula, different arrangement of atoms in space

Question 16

Why are heterogeneous catalysts greener than homogeneous?

Answer 16

They are easier to separate from the product and recycle

Question 17

what are the units for ideal gas equation?

Answer 17

p= pressure in pascals - Pa
V= volume in m^2
n= number of moles
R=gas constant 
T= temperature- K

Question 18

what is significant about gases at the same temperature and pressure?

Answer 18

they take up the same volume per mole

Question 19

what is the volume of 1 mole of gas at room temperature an pressure?

Answer 19

24dm^3

Question 20

what is the enthalpy change of reaction?

Answer 20

the enthalpy change when the reaction occurs in molar quantities shown in the chemical equation

Question 21

what is the enthalpy change of formation?

Answer 21

when one mole of product is formed from its elements in their standard states

Question 22

what is the enthalpy change of combustion?

Answer 22

enthalpy change when one mole of substance is completely burned in oxygen

Question 23

what is the enthalpy change of nuetralisation?

Answer 23

the enthalpy change when an acid and an alkali react together under standard conditions to form one mole of water

Question 24

what is average bond enthalpy?

Answer 24

the energy needed to break one mole of bonds in the gas phase averaged out over many compounds

Question 25

how can you measure enthalpy change

Answer 25

using calorimetry to measure temperature change of a reaction and then use q=mcΔT

Question 26

what is hess's law?

Answer 26

the total enthalpy change of a reaction is the same no matter which route is taken

Question 27

what is the relationship between bond enthalpy and bond length?

Answer 27

the larger the bond enthalpy, the shorter the bond due to greater attraction between the molecules

Question 28

what are the conditions needed for cracking?

Answer 28

passing hydrocarbon vapour over a heated solid catalyst or at really high temperature and pressures

Question 29

why is cracking done?

Answer 29

to make smaller hydrocarbons which are more useful

Question 30

what is a functional group?

Answer 30

a specific group of atoms in a molecule that are responsible for the caracteristic chemical reactions of that molecule

Question 31

what is a pi bond?

Answer 31

when 2 p orbitals overlap sideways, due to dumbell shape it forms below and above the molecular axis

Question 32

what is a sigma bond?

Answer 32

overlapping of two orbitals

Question 33

what does a double bond consist of?

Answer 33

a sigma and a pi bond

Question 34

what shape are saturated hydrocarbons?

Answer 34

tetrahedral

Question 35

what shape are unsaturated hyrdocarbons?

Answer 35

trigonal planar

Question 36

what can cause structural isomerism?

Answer 36

different carbon skeleton (branching) functional group in a different place different functional group

Question 37

what is the difference between E/Z and cis/trans?

Answer 37

E/Z must contain 1 hydrogen on each carbon in the c=c

Question 38

what is formed under electrophillic adition with: bromine hydrogen bromide water

Answer 38

dibromo alkane bromoalkane alcohol

Question 39

what are the conditions needed for electrophillic addition with water?

Answer 39

concentrated sulfuric acid and water or steam withh phosphoric acid catalyst at high temperature and pressure

Question 40

what is formed in complete combustion?

Answer 40

carbon dioxide and water

Question 41

what is formed in incomplete combustion?

Answer 41

carbon monoxide and water

Question 42

where do particulates come from and what are their implications?

Answer 42

from incomplete combustion- particles of liquid or carbon solid causes respiratory promblems and cardiovascular problems

Question 43

where do unburnt hydrocarbons come from and what are their implications?

Answer 43

from incomplete combustion can react in sunlight to form ground level ozone which can damage lungs

Question 44

where does carbon monoxide come from and what are their implications?

Answer 44

from incomplete combustion it is toxic

Question 45

where does carbon dioxide come from and what are their implications?

Answer 45

from combustion, it is a green house gas and causes global warming

Question 46

where does NOx come from and what are their implications?

Answer 46

fromed in engines under high pressure and temperatures when oxygen and nitrogen in the air react causes ground level ozone and photochemical smog

Question 47

where does SOx come from and what does it cause?

Answer 47

from burning hydrocarbons with sulfur impurities causes acid rain

Question 48

why is enthalpy change calculated experimentally smaller than the theoretical value?

Answer 48

heat is lost to the surroundings in complete combustion evaporation of fuel from the wick