What should be the range for the exponent of [H+] in solutions that are characterized as acidic?

A. 0 to -0.07
B. 0 to 0.7
C. 0 to -7
D. 0 to 7

4 answers

Acids have pH = 0 to pH = 7 so
pH = -log(H^+).
pH 0 then (H^+) = 1 x 10^0
pH 7 then (H^+) = 1 x 10^-7
sorry for commenting on a q that isn't mine but my calculator doesn't let me find the value for 10^-7. do you know why? and also what the value is?
That's perfectly ok. You aren't plugging it in right. On my calculator, if you hit the 10^x key then -7, you get the answer of 1E-7. If you're going the other way (that is, given (H^+) = 1E-7, and you want the pH), then hit the log button, type in 1E-7 and you will get -7, then change the sign (or multiply by -1) to get pH = 7.
The answer is C