MARK SCHEME definitions

Question 1

homologous series

Answer 1

(series of compounds)
- with the same functional group…
- with each successive member differing by CH2

Question 2

structural isomer

Answer 2

(compound with the) same molecular formula but different structural formula

Question 3

stereoisomer

Answer 3

(compounds with the) same structural formula but different arrangement of atoms in space

Question 4

enthalpy change of combustion

Answer 4

• enthalpy change that occurs when 1 mol of a substance…
• reacts fully with oxygen / completely combusts

// note complete combustion indicate its done so in excess oxygen so that all the substance has full reacted

Question 5

hydrocarbon

Answer 5

• compound ONLY made of carbon and hydrogen atoms

Question 6

standard enthalpy change of formation

// ‘standard’: asking to include standard conditions

Answer 6

• enthalpy change when 1 mol of a compound…
• is made from its elements (in their standard states)…
• standard conditions: 298K + 100KPa/1atm

Question 7

functional group

Answer 7

group of atoms (in molecule or compound) that is responsible for the reactions

Question 8

enantiomer

Answer 8

the type of isomers formed from optical isomerism

Question 9

standard electrode potential

Answer 9

the emf. of a half cell compared to the standard hydrogen half cell under 100KPa and 298K with solution concentrations being 1moldm-3