Question

what is C2H5 name?( compound)(CH2CH3)

Answer 1

Actually it's an group that we call Ethyl group.

For example

$\huge{CH_4}$:- Methane and if we remove 1 H atom then it become methyl group
i.e. $\huge{CH_3}$

Answer 2

Ch2ch5 is not possible. It is c2h6.

Ch3ch2 is ethane.