How many mL of 0.85 M KNO3 solution are needed to make 250.0 mL of 1.5 x 10-2 M solution?
Answers
To Find,
=> The mL of 0.85 M KNO3 solution required to make 250.0 mL of 1.5 x 10^-2 M KNO3 solution.
Concept Involved,
=> The concept of Molarity is utilized here.
=> Molarity of Solution (in molar) = (moles of solute) / (Litres of solution)
Let's Solve,
=> We need to make 250 mL of 1.5 x 10^-2 M KNO3 solution.
Molarity = 1.5 x 10^-2 => 0.015 M (molar)
Volume of solution = 250 mL => 250/1000 L => 0.25 L
Moles of KNO3 dissolved = ?
Molarity of Solution (in molar) = (moles of solute) / (Litres of solution)
=> 0.015 = (moles of solute) / (0.25)
=> moles of solute = 0.015 x 0.25 => 0.00375 moles of KNO3.
=> Now, we need to find the volume of 0.85 M KNO3 that has 0.00375 moles of KNO3 dissolved in it.
Molarity = 0.85 M (molar)
No. of moles of KNO3 = 0.00375 moles
Volume of solution (in litres) = ?
Molarity of Solution (in molar) = (moles of solute) / (Litres of solution)
=> 0.85 = 0.00375/(litres of solution)
=> litres of solution = 0.00375/0.85
=> litres of solution = 0.00441 litres
=> Volume of solution (in mL) = 0.00441 x 1000 mL => 4.41 mL