The molecular weight of an organic compound was found by mass spectrometry to be 70.042 11. Is the sample C5H10, C4H6O, or C3H6N2? Exact masses of elements are: 1.007 825 (1H); 12.000 00 (12C); 14.003 074 (14N); 15.994 915 (16O).

Verified step by step guidance

1. First, calculate the molecular weight of each compound using the exact masses of the elements provided. The molecular weight of a compound is the sum of the atomic weights of its constituent atoms.
2. For C5H10, the molecular weight would be (5 * atomic weight of C) + (10 * atomic weight of H).
3. For C4H6O, the molecular weight would be (4 * atomic weight of C) + (6 * atomic weight of H) + (1 * atomic weight of O).
4. For C3H6N2, the molecular weight would be (3 * atomic weight of C) + (6 * atomic weight of H) + (2 * atomic weight of N).
5. Finally, compare the calculated molecular weights with the given molecular weight (70.042 11). The compound with the molecular weight closest to the given value is the correct answer.

Key Concepts

Molecular Weight Calculation

Molecular weight, or molar mass, is the sum of the atomic weights of all atoms in a molecule. To determine the molecular weight of a compound, you multiply the number of each type of atom by its atomic weight and then sum these values. This calculation is essential for identifying compounds based on their mass spectrometry data.

Empirical Formula vs. Molecular Formula

The empirical formula represents the simplest whole-number ratio of elements in a compound, while the molecular formula indicates the actual number of each type of atom in a molecule. Understanding the difference is crucial when analyzing compounds, as the molecular weight can help determine which molecular formula corresponds to the measured mass.

Mass Spectrometry

Mass spectrometry is an analytical technique used to measure the mass-to-charge ratio of ions. It provides precise molecular weight data, allowing chemists to identify compounds based on their mass. In this context, the molecular weight obtained from mass spectrometry is compared against the calculated weights of potential molecular formulas to determine the correct compound.