Question

no cursive please

ONLY2 C AD [Review Topics) (References) Use the References to access important values If needed for this question. M M In which of the following pure substances would hydrogen bonding be expected? Choose all that apply. H 2reg acetone H- 4 H Visited propanamide H D H propyl formate H H H H propanoic acid H OH H H

Answer 1

Acetone

H.Bonding refers to both intramolecular and intermolecular. The oxygen atom of the carbonyl carbon withdraw electrons forming partial negative charge. the carbons of terminals also withdraw electrons forming partial positive hydrogens. both sides are partial positive hydogens but it will not form intramolecular hydrogen as due to symmetry as in fig.

a%3D0 |H、 CIH HH- HT H

However, intermolecular hydrogen is quite possible but only one and only with water and quite a weak hydrogen bond.

R Н LO R-C=O.....H-O

Propanamide

Primary amides have two hydrogen atoms on nitrogen that can involve in hydrogen bonding while secondary amides has only one hydrogen atom on the nitrogen atom that can involve in hydrogen bonding.

Propyl Formate

Propyl formate is a carbonyl compound and under normal circumstances you expect the carbonyl group which is very polar to interact with and hydrogen bond with water. However we have the effect of the carbon chain, This means that propyl formate is only partially soluble in water. So the answer is yes it would hydrogen bond because of the carbonyl group but it is not very soluble in water in the first place because of its carbons.

Propanoic Acid

Propionic acid has physical properties intermediate between those of the smaller carboxylic acids, formic and acetic acids, and the larger fatty acids. It is miscible with water, but can be removed from water by adding salt. As with acetic and formic acids, it consists of hydrogen bonded pairs of molecules as both the liquid and the vapor.