Table of contents

1. The Chemical World9m
- The Scientific Method
  9m
2. Measurement and Problem Solving2h 19m
3. Matter and Energy2h 15m
4. Atoms and Elements2h 33m
5. Molecules and Compounds1h 50m
6. Chemical Composition1h 23m
7. Chemical Reactions1h 43m
8. Quantities in Chemical Reactions1h 8m
9. Electrons in Atoms and the Periodic Table2h 32m
10. Chemical Bonding2h 10m
11 Gases2h 7m
12. Liquids, Solids, and Intermolecular Forces1h 11m
13. Solutions3h 1m
14. Acids and Bases2h 14m
15. Chemical Equilibrium1h 27m
16. Oxidation and Reduction1h 33m
17. Radioactivity and Nuclear Chemistry53m

6. Chemical Composition

Molecular Formula

Introduction to Chemistry

6. Chemical Composition

Molecular Formula

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Multiple Choice

What is the molecular formula for the following compound?
Empirical Formula: NPCl₂ Molar Mass:347.64 g/mol

NPCl₂

N₃P₃Cl₆

N₂P₂Cl₂

N₄P₄Cl₈

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Verified step by step guidance

Understand the relationship between empirical and molecular formulas. The empirical formula is the simplest whole-number ratio of atoms in a compound, while the molecular formula is the actual number of atoms of each element in a molecule.

Calculate the molar mass of the empirical formula NPCl2. Use the periodic table to find the atomic masses: Nitrogen (N) is approximately 14.01 g/mol, Phosphorus (P) is approximately 30.97 g/mol, and Chlorine (Cl) is approximately 35.45 g/mol.

Add the atomic masses to find the molar mass of the empirical formula: \( \text{Molar mass of NPCl}_2 = 14.01 + 30.97 + 2 \times 35.45 \).

Determine the ratio of the molar mass of the compound to the molar mass of the empirical formula. This ratio will tell you how many times the empirical formula must be multiplied to get the molecular formula.

Multiply the subscripts in the empirical formula by the ratio calculated in the previous step to find the molecular formula. This will give you the actual number of atoms of each element in the compound.