quantity vs so much

quantity

noun
  • A considerable measure or amount. 

  • Length of sounds. 

  • Indicates that the entire preceding expression is henceforth considered a single object. 

  • A fundamental, generic term used when referring to the measurement (count, amount) of a scalar, vector, number of items or to some other way of denominating the value of a collection or group of items. 

  • A specific measured amount. 

  • An indefinite amount of something. 

  • Property of a phenomenon, body, or substance, where the property has a magnitude that can be expressed as number and a reference. 

so much

noun
  • A particular amount, often a large or excessive amount. 

  • A demonstrated amount. 

adv
  • To a certain degree or extent 

adj
  • To such a quantity, degree etc. 

How often have the words quantity and so much occurred in a corpus of books? (source: Google Ngram Viewer )