pH of limewater question on chemistry quiz

[karma]

Randy,

I think there might be a problem with question #34 on your chemistry quiz.

The key is scoring answer "C" (12.15) as correct, but the explanation states the the correct pH is 12.45 (answer "D").

Also, the article that is linked on the "Answers" page for that question states 12.54.

Great quiz by the way!!

Michael

 

[Skipper]

Hey Michael. When did you take the test? We fixed it around 10am yesterday (or so we thought).

 

[karma]

Skip,

I took it before 10am. I went back later to look over the explanations on the ones I got wrong. That's when I noticed the problem.

So you guys probably had fixed it by then.

 

[Skipper]

Ok, thank you. That makes sense.

 

[Randy Holmes-Farley]

The error is still there, skipper:


34. The pH of saturated limewater (calcium hydroxide or calcium oxide dissolved in freshwater, also known as kalkwasser in German) at 25Ã"šÃ‚° C (77Ã"šÃ‚° F) is closest to:

A. 8.25
B. 9.2
C. 12.15
D. 12.45

Answer 34. Incorrect. You answered D. The pH of saturated limewater at 25Ã"šÃ‚° C (77Ã"šÃ‚° F) is 12.45. It is actually an established pH standard. The correct answer is C.