Question

According to the pattern of carbon and hydrogen atoms in alkenes, if a molecule has three carbon atoms, how many hydrogen atoms does it have?

Answer 1

Answer: The number of hydrogen atoms must be 6.

Explanation:

Alkenes are unsaturated hydrocarbons in which a single bond is present between carbon and hydrogen atoms and double bond is present between carbon and carbon atoms.

The general formula for writing an alkene is given as $C_nH_{2n}$ where, n = 1, 2, 3, 4....

It is given that number of carbon atoms are 3, which means that n = 3.

Putting (n = 3) in above expression, we get:

$n=3:C_3H_{2(3)}=C_3H_6$

Hence, the number of hydrogen atoms must be 6.

Answer 2

 6. 

Because the general formula for alkenes is CnH2n