Question

Define the following –

            (a)        Mole fraction              (b)        Parts Per Million

            (c)        Relative lowering of boiling point

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Answer 1

Answer:

a. the mole fraction or molar fraction is defined as unit of the amount of a constituent, nᵢ divided by the total amount of all constituents in a mixture.

b. the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they are pure numbers with no associated units of measurement.

c. The relative lowering of vapour pressure is the ratio of vapour pressure lowering of solvent from solution to the vapour pressure of pure solvent.

Answer 2

(a). From Wikipedia, the free encyclopedia. In chemistry, the mole fraction or molar fraction (xi) is defined as unit of the amount of a constituent (expressed in moles), ni divided by the total amount of all constituents in a mixture (also expressed in moles), ntot:.

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(b).Parts Per Million (ppm) Concentration Calculations

Write an equation representing the ppm concentration: ppm = mass solute (mg) ÷ volume solution (L)

Extract the data from the question: mass solute (NaCl) = 0.0045 g. ...

Convert the mass in grams to a mass in milligrams: mass NaCl = 0.0045 g = 0.0045 g × 1000 mg/g = 4.5 mg.

(c). don't know