Question

6.02 ×1019 molecules of urea(NH2CONH2) are present in 10 mL of its solution. Calculate the
molarity of the solution.

Answer 1

Answer:

Molarity of urea solution having 6.02 ×10¹⁹ molecule in 10 mL is 0.01 M

Explanation:

Given that,

number of molecules of urea = 6.02 ×10¹⁹

          volume of the solution = 10mL

1 mole ≡ Avogadro's number ≡ 6.02 × 10²³ molecules

Then,

    moles of urea = number of molecules / Avogadro's number

⇒                         =6.02 ×10¹⁹ / 6.02 × 10²³ = 1 × 10⁻⁴ mol

molarity of a solution is given by,

            $molarity = \frac{moles \;of \;solute}{liters \;of \;solution}$

⇒                         $=\frac{0.0001mol\times 1000mL}{10mL \times 1 L} = 0.01 M$

molarity of the urea solution is 0.01 M.