Textbook Question 1A.13

[Nina Fukui 2J]

For part c, how do I know which atoms bond with others? Do the parentheses help?

Draw the complete Lewis structure for each of the following compounds:
(a) formaldehyde, HCHO, which as its aqueous solution, “formalin,” is used to preserve biological specimens;
(b) methanol, CH3OH, the toxic compound also called wood alcohol;
(c) glycine, H2C(NH2)COOH, the simplest of the amino acids, the building blocks of proteins.

[Nane Onanyan 1G]

Hi! The way the compound is written out actually tells you the order you should draw them in. The parenthesis are there to emphasize a group. So the first carbon would have two hydrogens, an amine (NH2) group, and then connected to the next carbon. The second carbon would have an oxygen double bonded to it and a single bond with the OH group.

[Arieanne De Guzman 2J]

Yes, the parentheses do help in figuring out which atoms bond with others! Since NH2 is in parentheses, you would assume that those two hydrogens are specifically bonded to the nitrogen.

For part c, how do I know which atoms bond with others? Do the parentheses help?

Draw the complete Lewis structure for each of the following compounds:
(a) formaldehyde, HCHO, which as its aqueous solution, “formalin,” is used to preserve biological specimens;
(b) methanol, CH3OH, the toxic compound also called wood alcohol;
(c) glycine, H2C(NH2)COOH, the simplest of the amino acids, the building blocks of proteins.

[Sonel Raj 3I]

If its written out like it is there in the problem, then you would look at the formula to help you figure out what goes where! And the parentheses for sure are used to help you figure out where bonds should be placed. If the formula isn't written out and organized, then you would start with the element with the least ionization energy in the center and work your way around, making sure you check formal charges for what is most favorable!

[AlbertGu_2C]

The parentheses on the NH2 denote that the 2 hydrogens are only bonded to the N, which is bonded to the first C, which is denoted by how COOH is after the NH2