Question

4. Below is a set of pictorial diagrams representing five different stages of the reaction mixture during the titration of hydrochloric acid with sodium hydroxide as titrant. Water molecules, hydronium ions, chloride ions, and sodium ions in the various mixtures are shown. Har o H20t CI Nat a) List the diagrams by letter in the order these mixtures would appear during the titration, beginning with the earliest and ending with the final mixture. earliest final mixture A C b) Answer the following questions about the pictures above. i) If phenolphthalein is used as the indicator, which of the solutions would be: Colorless Pink Defend your choice. ii) Which diagram represents the endpoint of the titration? Defend your choice. ii) Which diagram represents the equivalence point of the titration? Acid Base Titration 6 p.

Answer 1

DATE PE NaOH + He Nach & HO NaOH is the tikant taken in the burette 1. Initially, in the conical flask, we have only Hel Cutece when Noot is added slowly the concentration of Nat will increase & finally it ion disappease Noteci lappear in equal concentration. learliest B D C 4 E final mixture. Bi has only at ions (due to Hel) Di has Nat but less concentration ciless number of water molecules compared to A Eu Natte are equal in concentration. 6) i colorless He pink NaOH il E because Nat & ce are in equal concentration with lot of water molecules. A because that is when the color change happens in tikation as it is nearing to the end of the reaction -