Compare the stabilities of the following two compounds :
$A$ : cis-$1$-Ethyl-$3$-methylcyclohexane
$B$ : trans-$1$-Ethyl-$3$-methylcyclohexane

The order of stability of the following tautomeric compounds is:
$(I) CH_2=C(OH)-CH_2-C(=O)-CH_3$
$(II) CH_3-C(=O)-CH_2-C(=O)-CH_3$
$(III) CH_3-C(OH)=CH-C(=O)-CH_3$

How many structural isomers are possible for $C_3H_6ClBr$ and how many of them are optically active?

Which pair represents chain isomers?

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

For which of the following parameters would the structural isomers $C_2H_5OH$ and $CH_3OCH_3$ be expected to have the same values? (Assume ideal behavior)