In the alkane H3C−CH2−C(CH3)2−CH2−CH(CH3)2, identify 1∘,2∘,3∘ carbon atoms and give the number of H atoms bonded to each one of these.
There are five- primary carbons as shown in the structure. Each 1∘ carbon atoms have three hydrogen atoms attached to them.
There are two secondary 2∘ carbon atoms, (2nd and 4th carbons) , they have two carbon atoms as their neighbours, & each has two hydrogen atoms attached.
There is only one tertiary carbon 3∘ ,which is bonded to three carbon atoms i.e., they have three carbon atoms as their neighbours and only one hydrogen atom is attached to it.