Multiple Choice
Cortisol (𝓜 = 362.47 g/mol), a known steroid hormone, is found to contain 69.6% carbon, 8.34% hydrogen, and 22.1% oxygen by mass. What is its molecular formula?
3775
views
6
rank
6. Chemical Reactions & Quantities
Molecular Formula
Multiple Choice
What is the molecular formula for the following compound?
Empirical Formula: NPCl2 Molar Mass: 347.64 g/mol
A
NPCl2
B
N3P3Cl6
C
N2P2Cl2
D
N4P4Cl8
Verified step by step guidance1
Understand the relationship between empirical and molecular formulas. The empirical formula represents the simplest whole-number ratio of atoms in a compound, while the molecular formula is a multiple of the empirical formula that matches the compound's molar mass.
Calculate the molar mass of the empirical formula NPCl2. Use the atomic masses: Nitrogen (N) = 14.01 g/mol, Phosphorus (P) = 30.97 g/mol, and Chlorine (Cl) = 35.45 g/mol. Add these together: 14.01 + 30.97 + 2(35.45).
Determine the factor by which the empirical formula must be multiplied to obtain the molecular formula. Divide the given molar mass of the compound (347.64 g/mol) by the molar mass of the empirical formula calculated in the previous step.
Multiply the subscripts in the empirical formula by the factor determined in the previous step to find the molecular formula. This involves multiplying each element's subscript in NPCl2 by the factor.
Verify that the calculated molecular formula matches one of the given options: N3P3Cl6, N2P2Cl2, or N4P4Cl8. Ensure that the molar mass of the calculated molecular formula is consistent with the given molar mass of 347.64 g/mol.
Related Videos
Related Practice
