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molecular weight

molecular weight

2 3.5
The total mass of the atoms in a molecule
  • noun
  • /məˈlɛkjələr weɪt/
  • Specialized
translation icon : peso molecular
  • The molecular weight of glucose is approximately 180 grams per mole.
  • low-molecular weight
  • high-molecular weight
  • average molecular weight

Examples

  • We're seeing spots of all different molecular weights, so from low to high on this gel.

  • Our first experiment is gonna be measuring... the molecular weight of butane.

  • The molecular weight is relative to...

  • And that's the difference in the molecular weight up here.

  • MMM is the molecular weight of the molecule in question.

  • So right down here, molecular weight, a chemist able to control molecular weight.

  • But since we need it in moles, we have to multiply times the molecular weight of water.

  • It's a high molecular weight coating, so it goes on thicker and it self levels.

  • Above these values, the effect of molecular weight on the dissolution rate is negligible.

    Academic text (2001)
  • They were like, what's the molecular weight of strontium?

Synonyms

relative molecular mass
vsmolecular weight
  • Specialized
5.6

The mass of all the atoms in one molecule compared with one twelfth of a carbon-12 atom

has identical meaning but used as the general measure of a molecule's mass

Surface Forms

Morphology

molecular + weight

The meaning 'the weight (heaviness) of a molecule' is directly and compositionally derived from 'molecular' (relating to molecules) + 'weight' (a measure of heaviness). Although the precise technical definition (sum of relative atomic masses) is specialized, the basic concept is transparent and mirrored across languages, so a B1 learner who knows the constituents would grasp the general meaning.

Etymology

The phrase molecular weight comes from a simple image: molecular means 'of a molecule' and weight is what you get when you add the weights of the atoms, like putting tiny pieces on a scale to get one number. So, molecular weight means 'the total mass of a molecule'.