Multiple choice: Soap in Hard Water. What is the correct solution and why?

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1 Answer
Nov 3, 2016

Answer:

Surely it is sample #A#?

Explanation:

You assess water hardness, and the Table gives you the means to do this. Sample #A# requires the most soap to give a decent lather. It also has the greatest boiling point, and the most precipitate when treated with #Ag^+# (i.e. the greatest concentration of #HO^-#).

I am willing to bet that if they had tabulated #pH# of each sample, sample #A# would have had the highest #pH#.