Answer: The molarity of given solution is 0.0235 M.
Step-by-step explanation:
Given : Volume of solution = 511 mL
Convert mL into L as follows.

Mass of
(solute) = 205 mg
Convert mg into gram as follows.

As molar mass of
is 17 g/mol. Hence, number of moles of
are calculated as follows.

Molarity is the number of moles of a solute dissolved in a liter of solution.

Substitute the values into above formula as follows.

Thus, we can conclude that the molarity of given solution is 0.0235 M.