How do I solve these?
[OH-]=3.2 X 10^-8 M (calculating the H3O+ ion concentration from the OH- ion concentration)
[H3O+]=7.3 X 10^-10 M (calculating the OH- ion concentration from the H3O+ ion concentration)
[OH-]=3.2 X 10^-8 M (calculating the H3O+ ion concentration from the OH- ion concentration)
[H3O+]=7.3 X 10^-10 M (calculating the OH- ion concentration from the H3O+ ion concentration)
1 Answer
You recall the value of
...remembering to use parentheses, or E notation to ensure proper scientific notation in your calculator.
...and at
K_w = ["H"_3"O"^(+)]["OH"^(-)] = 10^(-14)
for the reaction
2"H"_2"O"(l) rightleftharpoons "H"_3"O"^(+)(aq) + "OH"^(-)(aq) .
Thus,
color(blue)(["H"_3"O"^(+)]) = K_w/(["OH"^(-)]) = color(blue)(3.1_3 xx 10^(-7) "M") where the subscript indicates the digit past the last significant digit.
color(blue)(["OH"^(-)]) = K_w/(["H"_3"O"^(+)]) = color(blue)(1.3_7 xx 10^(-5) "M") where the subscript indicates the digit past the last significant digit.