The figure shows the displayed formulae of four molecules, A, B, C and D.
Figure: The displayed formulae of four molecules, A, B, C and D
Image brief: Four displayed formulae drawn side by side in a row, each inside its own thin rectangular box with the letter A, B, C or D printed beneath the box. A is ethane: two carbon atoms joined by a single line, each carbon also joined by single lines to three hydrogen atoms. B is ethene: two carbon atoms joined by two parallel lines, each carbon also joined by single lines to two hydrogen atoms. C is methanol: one carbon atom joined by single lines to three hydrogen atoms and to an oxygen atom, with that oxygen joined by a single line to one hydrogen atom. D is propane: three carbon atoms in a row joined by single lines, the two end carbons each joined to three hydrogen atoms and the middle carbon joined to two hydrogen atoms. Every atom shown as its element symbol, black on white, no colour and no shading, all bonds drawn as straight lines.
Give the letter of the molecule that is not a hydrocarbon. Give a reason for your answer.
Give the letters of the two molecules that are alkanes.
Write the molecular formula of molecule D.
Name molecule D.