# Which of the following options contains the LEAST number of covalent bonds on a mole for mole basis?

## $A .$ $H O {H}_{2} C - C {H}_{2} O H$ $B .$ $H O {H}_{2} C - C {H}_{3}$ $C .$ $H O \left(O =\right) C - C \left(= O\right) O H$ $D .$ $H O \left(O =\right) C - C {H}_{2} O H$

May 2, 2017

If I am reading this right, then it is $\text{option B}$........

#### Explanation:

$A .$ $H O {H}_{2} C - C {H}_{2} O H$ has $1 \times C - C$ bond, $4 \times C - H$ bonds, $2 \times C - O$ bonds, $2 \times O - H$ bonds, NINE bonds in total.

$B .$ $H O {H}_{2} C - C {H}_{3}$ has $1 \times C - C$ bond, $5 \times C - H$ bonds, $1 \times C - O$ bonds, $1 \times O - H$ bonds, EIGHT bonds in total.

$C .$ $H O \left(O =\right) C - C \left(= O\right) O H$ has $1 \times C - C$ bond $2 \times C = O$ bonds, $2 \times O - H$ bonds, NINE bonds in total if we count each $C = O$ as 2 bonds.

$D .$ $H O \left(O =\right) C - C {H}_{2} O H$ has $1 \times C - C$ bond $1 \times C = O$ bonds, $2 \times C - H$ bonds, $2 \times O - H$ bonds, $2 \times C - O$ bonds, NINE bonds in total if we count the $C = O$ as 2 bonds.

Do you agree with this count? It is easy to number the bonds if you write down the formulae on paper..............

Again, remember I counted $C = O$ AS TWO COVALENT BONDS.