Question

1. Draw the lewis structure of Butanal, which has the condensed formula CH3(CH2)2CHO. Show all hydrogen atoms and lone pairs of electrons?

2. Rank the given compunds based on their relative Bronsted relativities:

H-F
H-I
H-CH3
H-SH
H-NH2

According to me, the ans shud be H-I, H-SH, H-F, H-NH2-H-CH3, but this is wrong :(

These are easy questions, not even worth 175 points. Whoever gives me the correct answer, I ll surely give points.

Answer 1

Concepts and reason

According to octet rule, each atom forms bonds with other atoms until it gets eight electrons in its valence shell. The Lewis structures represent the number of bonds and lone pairs of electrons of all the atoms in the molecule.

If the atom attached to hydrogen is highly electro negative then it attracts the bonding pair of electrons towards itself more strongly. Hence, it releases the ions more easily. Therefore, the factor which affects the relative Bronsted acidities is the electronegativities of the atoms attached to hydrogen.

Fundamentals

According to Bronsted-Lowry theory an acid is a species which can donate ions in solution and base is a species which can acceptions in solution. If the species gives the ions more readily then it is a stronger acid.

Part 1

Count the total number of valence electrons in as follows:

Next draw the skeletal structure of shown as follows:

Draw the double bonds where ever necessary and show the remaining electrons as lone pairs to satisfy the octets of all the atoms (except hydrogen). Therefore, the Lewis structure of butanal is as follows:

Part 2

The order of electronegativity is as follows:

In case of halogens, the size takes more preference over electronegativity. As the size of I is higher than the size of F, it attracts the bonding pair of electrons more strongly. Hence, releases the ion more readily than.

The electronegativity of carbon and hydrogen are almost equal. Hence, cannot give ions in solutions. Hence, it is the weakest Bronsted acid.

Ammonia is basic due to the presence of lone pair of electrons and tends to accept protons rather than donate them. Hence, is less acidic than.

Therefore, the order of decreasing strength Bronsted acid is as follows:

Ans: Part 1

Therefore, the Lewis structure of butanal, is as follows:

Part 2

Therefore, the order of decreasing strength Bronsted acid is: