Question

2500 ml aq. solution of urea contains
$12 \times {10}^{24}$
units
of urea. The molarity of the solution is :- ( use
$n \ \: a \: = 6 \times {10}^{23}$
)​

Answer 1

Given info : 2500 ml aqueous solution of urea contains 12 × 10²⁴ units of urea.

To find : The molarity of the solution is ...

solution : we have given, 2500 mo aqueous solution of urea contains 12 × 10²⁴ molecules of urea.

no of moles = no of molecules/Avogadro's number

here given Avogadro's number = 6 × 10²³

so, no of moles = 12 × 10²⁴/(6 × 10²³) = 20

The molarity of the solution = no of moles of solute/volume of solution in L

= 20 mol/(2500/1000 L)

= 20/2.5

= 8 M

Therefore the molarity of the solution is 8 M.