Hydrocarbons Te...

$$CH_4+Cl_2\xrightarrow{hv} CH_3Cl+HCl$$

Arrange the following alkanes in decreasing order of their heats of combustion.
(i) $$\underset{(Neo-pentane) \, }{CH_3-\overset{CH_3}{\overset{|}{\underset{CH_3}{\underset{|}{C}}}}-CH_3}$$

$$CH_3-{\overset{CH_3}{\overset{|}C}}=CH_2 \, + \, (CH_3)_2CHCH_3 \, \xrightarrow[273K]{HF} \, C_8H_{18} \, (A)$$
Unknown $$(A)$$ in the above reaction is:

Halogenation is a substitution reaction, where halogen replaces one or more hydrogens of hydrocarbon.
Chlorine free radical make $$1^{\circ} ,2^{\circ} ,3^{\circ}$$ radicals with almost equal ease, whereas bromine free radicals have a clear preference for the formation of tertiary free radicals. So , bromine is less reactive, and more selective whereas chlorine is less selective and more effective.
The relative rate of abstraction of hydrogen by Br is
$$\underset{(1600)}{3^\circ} \, > \, \underset{(82)}{2^\circ} \, > \, \underset{(1)}{1^\circ}$$
The relative rate of abstraction of hydrogen by Cl is 
$$\underset{(5)}{3^\circ} \, > \, \underset{(3.8)}{2^\circ} \, > \, \underset{(1)}{1^\circ}$$
B.Above product will obtained in better yield if X is 

On halogenation, an alkane gives only one monohalogenated product. The alkane may be:

In the reaction,
$$C_6H_6+CO+HCl \xrightarrow[AlCl_3]{anhyd.}X+HCl$$ 

In the preparation of alkanes, a concentrated aqueous solution of sodium or potassium salts of saturated carboxylic acid are subjected to:

How many ionizable hydrogen's are there in the following compound?

The barrier for rotation about the indicated bond is only $$14\ kcal/mol$$. This barrier is much lower than the barrier for rotation about $$C=C$$ bond in ethylene. The smaller barrier in this compound is due to:

The arrangement of $${ \left( { CH }_{ 3 } \right)  }_{ 3 }C-,{ \left( { CH }_{ 3 } \right)  }_{ 2 }CH-,{ CH }_{ 3 }{ CH }_{ 2 }-$$ when attached to benzene or unsaturated group in increasing order of activating effect is: