A gaseous alkane on complete combustion gives CO-2 and H-2O- If the ratio of moles of O-2 needed combustion and moles of CO-2 formed is 5 - 3- out the formula of alkane-

Question

Toppr Admin · Accepted Answer

Let the alkane be -C-nH-2n - 2-C-nH-2n -2- - -left - n - -dfrac -n - 1-2- -right -O-2 -rightarrow nCO-2 - -n - 1-H-2O-dfrac - Mole-of-O-2-Mole-of-CO-2- - -dfrac -n - n-1-2-n- - -dfrac -5-3-160- -160- -160- -160- -160- -160- -160- -160- -160- -160- -160- -160- -160- -160- -160-n - 3-Thus alkane is -C-3H-8-

A gaseous alkane on complete combustion gives $$CO_2$$ and $$H_2O.$$ If the ratio of moles of $$O_2$$ needed for combustion and moles of $$CO_2$$ formed is $$5 : 3$$. find out the formula of alkane.

Let the alkane be $$C_nH_{2n + 2}$$

$$C_nH_{2n +2} + \left [ n + \dfrac {n + 1}{2} \right ]O_2 \rightarrow nCO_2 + (n + 1)H_2O$$

$$\dfrac { Mole\,of\,O_2}{Mole\,of\,CO_2} = \dfrac {n + n+1/2}{n} = \dfrac {5}{3}$$

$$n = 3$$

Thus alkane is $$C_3H_8$$.

A gaseous alkane on complete combustion gives $$CO_2$$ and $$H_2O.$$ If the ratio of moles of $$O_2$$ needed for combustion and moles of $$CO_2$$ formed is $$5 : 3$$. find out the formula of alkane.

Let the alkane be $$C_nH_{2n + 2}$$$$C_nH_{2n +2} + \left [ n + \dfrac {n + 1}{2} \right ]O_2 \rightarrow nCO_2 + (n + 1)H_2O$$$$\dfrac { Mole\,of\,O_2}{Mole\,of\,CO_2} = \dfrac {n + n+1/2}{n} = \dfrac {5}{3}$$ $$n = 3$$Thus alkane is $$C_3H_8$$.

Let the alkane be $$C_nH_{2n + 2}$$

$$C_nH_{2n +2} + \left [ n + \dfrac {n + 1}{2} \right ]O_2 \rightarrow nCO_2 + (n + 1)H_2O$$

$$\dfrac { Mole\,of\,O_2}{Mole\,of\,CO_2} = \dfrac {n + n+1/2}{n} = \dfrac {5}{3}$$

$$n = 3$$

Thus alkane is $$C_3H_8$$.