An alkene upon combustion produces CO 2 ( g ) and H 2 O ( g ) . In this combustion process if there is no volume change occurs then the no. of C atoms per molecule of alkene will be :

Question

An alkene upon combustion produces CO 2 ​ ( g ) and H 2 ​ O ( g ) . In this combustion process if there is no volume change occurs then the no. of C atoms per molecule of alkene will be :

TestHub · Accepted Answer

Question Explanation: Finding the condition for no volume change in combustion.

Concept: Stoichiometry of Gaseous Reactions.

Solution: For no volume change to occur in a gaseous reaction at constant T and P , the total volume (or moles) of gaseous reactants must equal the total volume (or moles) of gaseous products. We set up the general combustion equation for an alkene and solve for this condition.

Alkene

$C_{n} H_{2 n} (g) + \frac{3 n}{2} O_{2} (g) \to nCO_{2} (g) + nH_{2} O (g)$

if there no volume changes i.e. $Δ_{ng} = 0$

mole of (product - reactant) $= 0$

$(n + n) - (1 + \frac{3 n}{2}) = 0$

$2 n = 1 + \frac{3 n}{2}$

$n = 2$

∴ alkene $C_{2} H_{4}$ , no of atom of $C = 2$

Final Answer: B

Chemistry - Eudiometry Question with Solution | TestHub

Doubts & Discussion