Methylamine has a molecular formula of CH3N and the correct Lewis structure is the odor of rotten fish. Which dot structure is correct for methylamine? Choose one of the following: a) H-A-A-C-N-H-H b) H-C-N-H c) H-C=N-H d) H8-0-# A Provide the ionic formula for the following compounds: a) Potassium chloride b) Calcium hydroxide c) Sodium sulfide
The Correct Answer and Explanation is:
To answer the first question regarding methylamine’s correct Lewis dot structure, let’s break down the molecular formula CH3N.
- Methylamine consists of a methyl group (CH3) attached to an amine group (NH2).
- The central atom in methylamine is carbon (C), which is bonded to three hydrogens (H) and one nitrogen atom (N).
- The nitrogen atom in NH2 typically forms three bonds (two to hydrogens and one to carbon) and has a lone pair of electrons.
Now, looking at the options:
- Option a: H-H-H-C-N-H-H. This structure has an incorrect number of bonds for nitrogen (too many hydrogens).
- Option b: H-C-N-H. This structure places the lone pair of nitrogen appropriately, making it a valid choice.
- Option c: H-C=N-H. This structure suggests a double bond between carbon and nitrogen, which isn’t correct since nitrogen can only form one bond with carbon here.
- Option d: The image you provided seems to have some formatting issues and doesn’t correspond to any valid structure.
Thus, the correct structure for methylamine is Option b: H-C-N-H, where nitrogen has a lone pair and forms single bonds with both carbon and hydrogen.
For the ionic formulas:
- Potassium chloride (KCl): Potassium (K) has a charge of +1, and chlorine (Cl) has a charge of -1, so the ionic formula is KCl.
- Calcium hydroxide (Ca(OH)2): Calcium (Ca) has a charge of +2, and hydroxide (OH) has a charge of -1, so we need two hydroxide ions to balance the charge, giving the formula Ca(OH)2.
- Sodium sulfide (Na2S): Sodium (Na) has a charge of +1, and sulfur (S) has a charge of -2. To balance the charges, we need two sodium ions, so the ionic formula is Na2S.
