Molar Mass Distribution - Definition of Molar Mass Averages

Definition of Molar Mass Averages

Different average values can be defined depending on the statistical method that is applied. The weighted mean can be taken with the weight fraction, the mole fraction or the volume fraction:

  • Number average molar mass or Mn
  • Weight average molar mass or Mw
  • Viscosity average molar mass or Mv
  • Z average molar mass or Mz

M_n=\frac{\sum M_i N_i} {\sum N_i}, M_w=\frac{\sum M_i^2 N_i} {\sum M_i N_i}, M_z=\frac{\sum M_i^3 N_i} {\sum M_i^2 N_i}, M_v=\left^\frac{1} {a}

Here a is the exponent in the Mark-Houwink equation that relates the intrinsic viscosity to molar mass.

Read more about this topic:  Molar Mass Distribution

Famous quotes containing the words definition of, definition and/or mass:

    “Definition of a classic: a book everyone is assumed to have read and often thinks they have.”
    —Alan Bennett (b. 1934)

    “According to our social pyramid, all men who feel displaced racially, culturally, and/or because of economic hardships will turn on those whom they feel they can order and humiliate, usually women, children, and animals—just as they have been ordered and humiliated by those privileged few who are in power. However, this definition does not explain why there are privileged men who behave this way toward women.”
    —Ana Castillo (b. 1953)

    “It is a mass language only in the same sense that its baseball slang is born of baseball players. That is, it is a language which is being molded by writers to do delicate things and yet be within the grasp of superficially educated people. It is not a natural growth, much as its proletarian writers would like to think so. But compared with it at its best, English has reached the Alexandrian stage of formalism and decay.”
    —Raymond Chandler (1888–1959)