When a hydrocarbon A undergoes combustion in the presence of air, it requires 9.5 equivalents of oxygen and produces 3 equivalents of water. What is the molecular formula of A ?

Question

When a hydrocarbon A undergoes combustion in the presence of air, it requires 9.5 equivalents of oxygen and produces 3 equivalents of water. What is the molecular formula of A ? (A) C 8 H 6 (B) C 9 H 9 (C) C 6 H 6 (D) C 9 H 6

Tardigrade Admin · Accepted Answer

C x H y +( x +( y /4)) O 2 arrow xCO 2+( y /2) H 2 O x +( y /4)=9.5 ( y /2)=3 ⇒ x =8, y =6

Q. When a hydrocarbon A undergoes combustion in the presence of air, it requires $9.5$ equivalents of oxygen and produces $3$ equivalents of water. What is the molecular formula of $A$ ?

$C_{8} H_{6}$

$C_{9} H_{9}$

$C_{6} H_{6}$

$C_{9} H_{6}$

$C_{x} H_{y} + (x + \frac{y}{4}) O_{2} \to x C O_{2} + \frac{y}{2} H_{2} O$
$x + \frac{y}{4} = 9.5$
$\frac{y}{2} = 3$
$\Rightarrow x = 8, y = 6$

Q. When a hydrocarbon A undergoes combustion in the presence of air, it requires 9.5 equivalents of oxygen and produces 3 equivalents of water. What is the molecular formula of A ?

C8​H6​

C9​H9​

C6​H6​

C9​H6​