Question

You need to prepare 250.0 mL of a 1.35 M HCl solution from a 4.50 M HCl stock solution. Glassware A is a 250 m L beaker. Glassware B is a 250 m L erlenmeyer flask. Glassware C is a 250 m L volumetric flask. Assuming that the accuracy of the concentration is important, which type of glassware should you use to make the solution

Answer 1

Answer: Glassware C

Explanation:

According to moalrity equation:

$M_1V_1=M_2V_2$

$M_1$ = Molarity of stock solution = 4.50 M

$V_1$ = volume of stock solution = ?

$M_2$ = molaity of diluted solution = 1.35 M

$V_2$ = volume of diluted solution = 250.0 ml

$4.50\times V_1=1.35\times 250.0$

$V_1=75.0ml$

A volumetric flask is more accurate for making solutions than a beaker or erlenmeyer flask and hence to measure 75.0 ml of stock solution , we use 250 ml  of volumetric flask.

Thus 75.0 ml of stock is pipetted out using pipette and put into a volumetric flask of 250 ml and water is added till the mark reaches 250 ml.

A volumetric flask is more accurate for making solutions than a beaker or erlenmeyer flask and hence to measure 75.0 ml of stock solution , we use 250 ml  of volumetric flask.