molecular weight

noun

, Chemistry.

1. the average weight of a molecule of an element or compound measured in units once based on the weight of one hydrogen atom taken as the standard or on 1/16 (0.0625) the weight of an oxygen atom, but after 1961 based on 1/12 (0.083) the weight of the carbon-12 atom; the sum of the atomic weights of all the atoms in a molecule. : mol. wt.

molecular weight

noun

1. the former name for relative molecular mass

molecular weight

1. The sum of the atomic weights of the atoms contained in a molecule.
2. Also called relative molecular mass

molecular weight

1. The sum of the atomic weights of all the atoms in a molecule .

Word History and Origins

Origin of molecular weight¹

First recorded in 1875–80

Example Sentences

Since the molecular weight of salt is very small, we use a special membrane that filters it through very small holes that allows only these molecules to pass through.

From Salon

Further, hydrophobicity and molecular weight both had an influence on preventing protein aggregation and enhancing protein stabilization.

From Science Daily

Since chitin is a very high molecular weight polysaccharide, traditional processing techniques rely on caustic chemicals to break it down.

From Science Daily

Additionally, the water content affects the total molecular weight of the compound that is needed for the calculation of the correct drug dosage.

From Science Daily

Adds Dr. Cleaves: "From a chemical standpoint, the differences between biotic and abiotic samples relate to things like water solubility, molecular weights, volatility and so on."

From Science Daily