Question

The general molecular formula of nitroalkanes is

• A. $C_nH_{2n}NO_2$
• B. $C_{n+1}H_{2n+3}NO_2$
• C. $C_{n+1}H_{2n}NO_2$
• D. $C_{n+1}H_{2n+2}NO_2$

Answer 1

Answer: (B)

$C_{n+1}H_{2n+3}NO_2$

Answer 2

The general formula for an alkane is $C_xH_{2x+2}$. A nitroalkane is formed by replacing one hydrogen atom with a nitro group (-NO₂). Therefore, the general formula for a nitroalkane with 'x' carbon atoms is $C_xH_{2x+1}NO_2$.

Option (2) is $C_{n+1}H_{2n+3}NO_2$. If we let the number of carbon atoms be $x = n+1$, then $n = x-1$. Substituting this into the hydrogen count: $2n+3 = 2(x-1)+3 = 2x-2+3 = 2x+1$.

So, option (2) can be rewritten as $C_xH_{2x+1}NO_2$, which is the correct general formula for nitroalkanes.