gram molecule: meaning, definition, pronunciation and examples
C2Technical / Historical (Chemistry)
Quick answer
What does “gram molecule” mean?
A quantity of a substance (compound or element) whose mass in grams is numerically equal to its molecular weight or atomic weight, respectively.
Audio
Pronunciation
Definition
Meaning and Definition
A quantity of a substance (compound or element) whose mass in grams is numerically equal to its molecular weight or atomic weight, respectively; synonymous with 'mole' in modern chemistry.
In historical or pedagogical chemistry contexts, a specific term for the amount of a molecular substance equal to its relative molecular mass expressed in grams, now largely superseded by the SI unit 'mole'. Can also refer, in some contexts, to the concept of a mole as applied specifically to molecular entities.
Dialectal Variation
British vs American Usage
Differences
No significant lexical difference; both regions have transitioned to using 'mole'. The term 'gram molecule' is equally archaic in both.
Connotations
Connotes mid-20th-century chemistry education or foundational textbooks. May be used by older educators or in very specific historical discussions.
Frequency
Extremely low and declining in both varieties. It is a historical/technical fossil term.
Grammar
How to Use “gram molecule” in a Sentence
One gram molecule of [SUBSTANCE] contains...The volume occupied by a gram molecule of gas...[Number] gram molecules of [SUBSTANCE] were used.Vocabulary
Collocations
Examples
Examples of “gram molecule” in a Sentence
adjective
British English
- The gram-molecule concept is foundational.
- He referred to the gram-molecular volume.
American English
- The gram-molecule approach is outdated.
- She calculated the gram-molecular mass.
Usage
Meaning in Context
Business
Not used.
Academic
Rarely used in modern academic papers. May appear in historical reviews or the history of science.
Everyday
Never used.
Technical
The primary domain. Used almost exclusively in chemistry, and even there it is outdated. Found in legacy documentation, some older lab manuals, or explanatory footnotes.
Vocabulary
Synonyms of “gram molecule”
Vocabulary
Antonyms of “gram molecule”
Watch out
Common Mistakes When Using “gram molecule”
- Using 'gram molecule' in modern scientific writing instead of 'mole'.
- Confusing it with 'gram atomic weight' or 'gram formula weight', which apply to elements and ionic compounds respectively.
- Treating it as plural incorrectly (e.g., 'grams molecule').
FAQ
Frequently Asked Questions
Yes, in essence. A gram molecule is an older term for the amount of a molecular substance that has a mass in grams equal to its molecular weight, which is exactly the definition of a mole for molecular substances.
You are most likely to encounter it in historical scientific texts, older chemistry textbooks (pre-1970s), or occasionally when an instructor is explaining the historical development of the mole concept.
No, not directly. For elements, the equivalent historical term is 'gram atom' or 'gram atomic weight'. The modern term 'mole' applies universally to all substances (elements, molecules, ions).
The International System of Units (SI) adopted 'mole' (symbol 'mol') as the base unit for amount of substance in 1971 to create a unified, simpler terminology applicable to all chemical entities (atoms, molecules, ions, electrons), not just molecules. This streamlined scientific communication.
A quantity of a substance (compound or element) whose mass in grams is numerically equal to its molecular weight or atomic weight, respectively.
Gram molecule is usually technical / historical (chemistry) in register.
Gram molecule: in British English it is pronounced /ˌɡræm ˈmɒlɪkjuːl/, and in American English it is pronounced /ˌɡræm ˈmɑːləkjuːl/. Tap the audio buttons above to hear it.
Learning
Memory Aids
Mnemonic
Think: GRAMs of a MOLECULE's weight. If the molecule weighs 18 (like water, H₂O), one GRAM MOLECULE is 18 grams of it.
Conceptual Metaphor
A STANDARDISED PACKAGE of molecules. Conceptualised as a fixed, countable 'packet' of substance, scaled up from the microscopic molecular world to a manageable, weighable amount in the lab.
Practice
Quiz
Which of the following is the modern, preferred term for 'gram molecule'?