20 questions-organic chemistry Flashcards
whats a hydrocarbon
a substance with molecules that only contain carbon and hydrogen atoms
how many bonds do carbon atoms form
4
whats the general formula of an alkane
CnH2n+2
name the first 4 alkanes
methane,ethane,propane,butane
how does boiling point change with the length of an alkane
the longer the alkane molecule the higher its boiling point
whats the chemical formula for propane
c3h8
write the balanced symbol equation for the complete combustion of methane
CH4 + 2O2 → CO2 + 2H2O
why are alkenes more reactive than alkanes
Because they contain at least one C=C double bond (they are unsaturated), so they have the capacity to make further bonds.
complete the equation for the cracking of octane C8H18->C6H14+—
C2H4
pentene has 5 carbon atoms,whats the formula for pentene
c5h10
why do alkenes burn with smoky flames
incomplete combustion
how can a sample of butane be told apart from a sample of butene
add bromine water and shake.butene is an alkene and decolourises the bromine water whereas butane doesnt react so it stays orange
whats the ideal temp for the fermentation of glucose
25 to 50 degrees
give the formula for the 4th member of the homolougs series of alcohols
C4H9OH
give formula for the 4th member of carboxylic acid
c3h7cooh
