Question

A chemist prepares a solution of nickel(II) chloride NiCl2 by measuring out 21.μmol of nickel(II) chloride into a 200.mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in /mmolL of the chemist's nickel(II) chloride solution. Round your answer to 2 significant digits.

Answer 1

Answer:

$Concentration=0.11\ mmol/L}$

Explanation:

Given that:-

Moles of the salt, $NiCl_2$ = 21 μmol

Also, 1 μmol = 0.001 mmol

So,

Moles = 0.021 mmol

Given that:- The volume = 200 mL

Also, 1 mL = 0.001 L

So, Volume = 0.2 L

Thus,

$Concentration=\frac{Moles\ of\ solute}{Volume\ of\ the\ solution}$

$Concentration=\frac{0.021\ mmol}{0.2\ L}$

$Concentration=0.11\ mmol/L}$