The higher stabilities of $tert$-butyl cation over isopropyl cation and $trans-2-butene$ over propene,respectively,are due to orbital interactions involving

Arrange the following according to the instructions:
$(i)$ Arrange in descending order of acidic strength:
$CH_3COOH, (CH_3)_3CCOOH, (CH_3)_2CHCOOH, CH_3CH_2COOH$
(ii) Arrange in descending order of stability:
$\stackrel{+}{CH}_3, (CH_3)_3\stackrel{+}{C}, CH_3CH_2^+, (CH_3)_2\stackrel{+}{CH}$
(iii) Arrange in increasing order of acidic strength:
$CCl_3COOH, CH_3COOH, CHCl_2COOH, CH_2ClCOOH$
(iv) Arrange in increasing order of stability:
$(a)$ $CH_3CH=CH-CHO$
$(b)$ $CH_3\stackrel{+}{CH}-CH=C-O:^-$
$(c)$ $\stackrel{+}{CH}_2-CH=CH-C=O$
$(v)$ Arrange in decreasing order of stability:
$(I)$ $CH_2=CH-CHO$
$(II)$ $\stackrel{+}{CH}_2-CH=C-H$ (with $O^-$)
$(III)$ $:CH_2-CH=C-H$ (with $O^-$)

Write the correct order of acidic strength for the following:
$(I) \ CH_3 - NO_2$
$(II) \ NO_2 - CH_2 - NO_2$
$(III) \ CH_3 - CH_2 - NO_2$
$(IV) \ (NO_2)_3CH$

The decreasing order of reactivity towards electrophilic substitution for the following compounds is:

Match column $-I$ and column $-II$ with the correct electronic effect relation:

Column $-I$	Column $-II$
$(i)$ $C_6H_5NH_2$	$(p)$ $-R$ effect
$(ii)$ $C_6H_5OH$	$(q)$ $+R$ effect
$(iii)$ $C_6H_5NO_2$	$(r)$ $+I$ effect
$(iv)$ $CH_3CH_2Cl$	$(s)$ $-I$ effect

Identify the functional group that has electron donating inductive effect.