question_answer 65)

  Which of the following terms are unitless? (a) Molality                         (b) Molarity (c) Mole fraction              (d) Mass per cent

Answer:

  (c, d) Mole fraction, \[{{x}_{A}}=\frac{{{n}_{A}}}{{{n}_{A}}+{{n}_{B}}}=\frac{\text{Moles}\,\text{of}\,\text{a}\,\text{component}}{\text{Total}\,\text{number}\,\text{of}\,\text{moles}}\]   (unitless) \[Mass\,percentage=\frac{Mass\,of\,a\,component}{Total}\times 100(unitless)\]