A student prepares three potassium nitrate solutions as described below
CHEMISTRY · Multi-part · AP · Chemistry · Atomic Structure and Properties · Atomic Structure and Properties
Problem
A student prepares three potassium nitrate solutions as described below.
Solution P: 12.0 g of KNO3 are placed in a 250 mL volumetric flask and water is added until the meniscus reaches the calibration line.
Solution Q: 20.0 g of KNO3 are placed in a 500 mL volumetric flask and diluted to the mark.
Solution R: 9.0 g of KNO3 are placed in a 200 mL volumetric flask and diluted to the mark.
Answer the following questions about the relative concentrations of the three solutions. (Molar mass of KNO3 = 101gmol−1.)
(a) Identify which solution is the most concentrated and which is the least concentrated without computing the exact molarity values.
(b) Provide a step-by-step justification for your answer to part (a) that makes explicit use of mole-to-volume ratios.
(c) If the student wishes to adjust solution Q so that its concentration matches that of solution P, determine the minimum additional volume of water (in mL) that must be added to solution Q. Show all reasoning.