Formula Unit Mass Definition
Formula unit mass is the sum of the atomic masses of all the atoms represented in the chemical formula of a substance. This term is primarily used for ionic compounds, which exist as extended crystal lattices rather than discrete molecules. The formula unit represents the simplest whole-number ratio of ions in the compound.
Analyzing the Options
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Option D: The total mass of all atoms in one formula unit of a compound
This is the correct definition. For instance, the formula unit mass of Magnesium Chloride (MgCl2) is calculated by summing the atomic mass of one Magnesium (Mg) atom and the atomic masses of two Chlorine (Cl) atoms.
Calculation: Formula Unit Mass (MgCl2) = Atomic Mass (Mg) + 2 * Atomic Mass (Cl) -
Option A: The mass of a single molecule of an element
This describes molecular mass, which applies to substances that exist as molecules (e.g., O2, H2O). -
Option B: The mass of a single atom of an element
This describes atomic mass. -
Option C: The mass of one mole of a substance
This describes molar mass, representing the mass of Avogadro's number of particles.
Based on these definitions, Option D accurately explains the term 'formula unit mass'.
Important Questions from Basic Concepts of Chemistry
Which of the following given below is an alloy of mercury?
The chemical symbol of potassium is _______.
In a molecule of water, the ratio of the mass of hydrogen to that of oxygen is:
Which is the element having the highest atomic mass among the following?
Each water molecule, contains _______ hydrogen atoms and one Oxygen atom.
