Question

What is the osmolarity of .00001 grams (0.1 mg%) of ethanol (does not dissociate) in one liter?

Answer 1

Step-by-step explanation:

As it is known that non-electrolytes do not dissociate. Therefore, molarity of such a solution is equal to the osmolarity of solution.

As, molar mass of ethanol = 46.07 g/mol

Therefore, no. of moles of ethanol will be calculated as follows.

No. of moles =
`\frac{mass}{\text{molar mass}}`

=
`(0.00001 g)/(46.07 g/mol)`

=
`2.17 * 10^(-7)` mol

As, molarity is moles of solute in liter of solution. Hence, molarity of ethanol is as follows.

Molarity =
`\frac{\text{no. of moles}}{volume}`

=
`(2.17 * 10^(-7) mol)/(1 L)`

=
`2.17 * 10^(-7)` mol/L

Since, for the given solution Molarity = osmolarity

Thus, we can conclude that osmolarity of .00001 grams (0.1 mg%) of ethanol in 1 L is
`2.17 * 10^(-7)` osmol/L.