Which of the following is an isomer of ethanol $(C_2H_5OH)$?

The number of isomers of $C_4H_{10}$ is:

Identify the pairs of compounds that represent position isomerism:
$(I)$ $CH_3-CH_2-CH_2-CH_2-OH$
$(II)$ $CH_3-CH_2-CH(OH)-CH_3$
$(III)$ $CH_3-C(CH_3)(OH)-CH_3$
$(IV)$ $CH_3-CH(CH_3)-CH_2-OH$
$(V)$ $CH_3-CH_2-O-CH_2-CH_3$
$(VI)$ $CH_3-O-CH_2-CH_2-CH_3$
$(VII)$ $CH_3-O-CH(CH_3)-CH_3$

$CH_3-CH_2-NH-CHO$ and $CH_3-CH(NH_2)-CHO$ are

Which of the following pairs of compounds is an example of position isomerism?

Which of the following compounds is asymmetric?