What is the molar mass (formula weight) of Ca(NO3)2? Provide your answer to two decimal places.

• A. 136.09 g/mol
• B. 102.09 g/mol
• C. 164.10 g/mol
• D. 180.16 g/mol

Answer: (C)

Verified step by step guidance

1. Identify the chemical formula of the compound: Ca(NO3)2, which consists of 1 calcium (Ca) atom, 2 nitrogen (N) atoms, and 6 oxygen (O) atoms (since there are 2 nitrate ions, each containing 3 oxygen atoms).
2. Find the atomic masses of each element from the periodic table: calcium (Ca) ≈ 40.08 g/mol, nitrogen (N) ≈ 14.01 g/mol, and oxygen (O) ≈ 16.00 g/mol.
3. Calculate the total mass contributed by each element by multiplying the atomic mass by the number of atoms in the formula: for Ca, multiply 40.08 g/mol by 1; for N, multiply 14.01 g/mol by 2; for O, multiply 16.00 g/mol by 6.
4. Add all these contributions together to get the molar mass of Ca(NO3)2: \(\text{Molar mass} = (1 \times 40.08) + (2 \times 14.01) + (6 \times 16.00)\) g/mol.
5. Sum the values from the previous step to find the total molar mass, and then round your answer to two decimal places as requested.