A student is instructed to prepare a dilute sodium hydroxide solution for a titration
CHEMISTRY · Multi-part · A Level · Chemistry · Amount of substance · Amount of substance
Problem
A student is instructed to prepare a dilute sodium hydroxide solution for a titration. The procedure is as follows:
• Step 1 Dissolve 2.50 g of NaOH pellets in a 500.0 mL volumetric flask and dilute to the mark with deionized water.
• Step 2 Pipet 50.0 mL of the solution from Step 1 into a second 250.0 mL volumetric flask and again dilute to the mark with deionized water.
• Step 3 Label the final solution as “NaOH (aq)” for use in the titration.
Atomic masses (g mol⁻¹): Na 22.99, O 16.00, H 1.01
(1) Calculate the molarity of the solution prepared in Step 1.
(2) Using your result from Step 1, determine the number of moles of NaOH transferred to the second volumetric flask in Step 2.
(3) Calculate the molarity of the final NaOH solution obtained after Step 2.
(4) If the student accidentally used 55.0 mL instead of 50.0 mL in Step 2 but still diluted to 250.0 mL, predict qualitatively and quantitatively how the molarity of the final solution would be affected. Show any calculations to support your answer.