Solution A contains 6 g of urea in 100 mL of it at `27^(@)C` whiole solution B has 6 g of acetic acid in 100 mL of the solution at the same temperature. Are the two solutions equimolar as well as isotonic ?

Explanation

Comparing the molarities of the two solutions.
`"Molarity (M)"=("Mass of urea/Molar mass of urea")/("Volume of slution in litres")`
`((6g)//(60 g mol^(-1)))/(0.1L)=1 mol^(-1)= 1 M`
`"Molarity (M)"=("Mass of acetic acid / Molar mass of acetic acid")/("Volume of slution in litres")`
`((6g)//(60 g mol^(-1)))/(0.1L)=1 mol^(-1)= 1 M`
Solution A and B are equimolar.
Comporing the osmotic pressures of the two solutions.
For solution A: `pi=iCRT=1xx(1 mol L^(-1))xx(0.0821 L atm K^(-1) mol^(-1))xx300 K`
=24.63 atm
Acetic acid ionises in aqueous solution as:
`CH_(3)COOH+H_(2)OLeftrightarrowCH_(3)COO^(-)(aq)+H_(3)O^(+)(aq)`
In this case, Can't Hoff factor ` (i) gt 1`
`pi=iCRT gt24.63 atm`
Since the two solutions have different osmotic pressurs, these are not isotnic.