Question

The total number of electrons and the number of electrons involved in the formation of various bonds present in one molecule of propanal $\left(C_2{H}_{5}CHO\right)$ are respectively.

• A. $32$ and $20$
• B. $24$ and $20$
• C. $24$ and $18$
• D. $32$ and $18$

Answer 1

The correct option is A $32$ and $20$

Number of bonds in propanal are 10. Each bond is made of 2 electrons. Hence, the number of electrons involved in the formation of various bonds present in one molecule of propanal is $10\times 2=20$
The molecular formula of prpanal is $\left(C_2{H}_{5}CHO\right)$ or $\left(C_3{H}_{6}O\right)$
Each C atom has 6 electrons.
Each H atom has 1 electrons.
Each O atom has 8 electrons.
Hence, the number of electrons present in one molecule of propanal $=3\left(6\right)+6\left(1\right)+8=32$