What is the molar mass of NH_3?

• A. 15.0 g/mol
• B. 17.0 g/mol
• C. 16.0 g/mol
• D. 18.0 g/mol

Answer: (B)

Verified step by step guidance

1. Identify the chemical formula of the compound, which is NH_3 (ammonia).
2. Determine the atomic masses of each element from the periodic table: nitrogen (N) has an atomic mass of approximately 14.0 g/mol, and hydrogen (H) has an atomic mass of approximately 1.0 g/mol.
3. Count the number of atoms of each element in the formula: there is 1 nitrogen atom and 3 hydrogen atoms in NH_3.
4. Calculate the total mass contributed by each element by multiplying the atomic mass by the number of atoms: for nitrogen, multiply 14.0 g/mol by 1; for hydrogen, multiply 1.0 g/mol by 3.
5. Add the masses of all atoms together to find the molar mass of NH_3: total molar mass = (14.0 g/mol) + (3 × 1.0 g/mol).