Which of the following statements is incorrect for alkanes?

Write the method of preparation for hydrocarbons by the decarboxylation of carboxylic acids.

In the reaction $CH_3-Br + 2Na + Br-CH_3 \to$,the product is called

$RMgI$ when treated with ice-cold water liberated a gas which occupied $1.4 \text{ dm}^3/\text{g}$ at $STP$. The gas produced is further reacted with iodine in the presence of $HIO_3$ to give compound $(X)$. Compound $(X)$ in the presence of $Na$ and dry ether produced compound $(Y)$. The molar mass of compound $(Y)$ is . . . . . . $\text{g mol}^{-1}$. (Nearest integer)

The reaction of an alkyl bromide $(X)$ with $Na$ in dry ether gives $4, 5-$diethyl octane. Then $(X)$ is:

When are the compounds called normal $(n-)$? Give an example.