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
-
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 one of the following is a chemical change?
Which one of the following methods can be used to separate anthracene from a mixture of salt and anthracene ?
Which among the following are essential constituents of Portland cement?
20 g of common salt is dissolved in 180 g of water. What is the mass percentage of the salt in the solution?
Combination of one volume of nitrogen with three volumes of hydrogen produces
