The iupac rules permit the use of common names for a number of familiar phenols and aryl ethers. these common names are listed here along with their systematic names. write the structure of each compound.

a. vanillin(4-hydroxy-3-methoxybenzald ehyde): a component of vanilla bean oil, which contributes to its characteristic flavor.
b. thymol (2-isopropyl-5-methylphenol): obtained from oil of thyme.
c. carvacrol (5-isopropyl-2-methylphenol): present in oil of thyme and marjoram.
d. eugenol (4-allyl-2-methoxyphenol): obtained from oil of cloves.
e gallic acid (3,4,5-trihydroxybenzoic acid): prepared by hydrolysis of tannins derived from plants.
f. salicyl alcohol (o-hydroxybenzyl alcohol): obtained from bark of poplar and willow trees.

Explanation:

a. Vanillin(4-hydroxy-3-methoxybenzaldehyde):

In its structure hydroxl group will be present on para position of the benzaldehyde ring and methoxy group on meta position.

b. Thymol (2-isopropyl-5-methylphenol):

In its structure isopropyl group will be present on ortho position of the phenol ring and methyl group on meta position.

c. Carvacrol (5-isopropyl-2-methylphenol):

In its structure isopropyl group will be present opposite to methyl group which is present ortho position in a phenol ring.

d. Eugenol (4-allyl-2-methoxyphenol):.

In its structure allyl group will be present on para position of the phenol ring and methoxy group on ortho position.

e. Gallic acid (3,4,5-trihydroxybenzoic acid):

In its structure hydroxyl group will be present on both meta positions and on para position of the benzoic acid ring.

f. Salicyl alcohol (o-hydroxybenzyl alcohol):

In its structure, group is linkedto benzene ring and in respect to that hydroxyl group is present at ortho position of the ring.

the maximum mass of nh3 is nh3 in grams

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.