Chem

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Please tell me if these are right!

What are the [H3O+] and [OH-] for a solution with the following pH values?

a. 10.0 I got 1.0*10^-10 for [H3O+] and 1.0*10^-4 for [OH-]

b. 5.0 I got 1.0*10^-5 for [H3O+] and 1.0*10^-9 for [OH-]

c. 7.00 I got 1.0*10^-7 for [H3O+] and1.0*10^-7 for [OH-]

d. 6.5 I got 3.2*10^-7 for [H3O+] and 3.125*10^-8 for [OH-]

e. 1.82 I got 1.5*10^-2 for [H3O+] and 6.7*10^-12 for [OH-]

Solution X has a pH of 9.5 and solution Y has a pH of 7.5.

b. what is the [H3O+] in each?
I got 3.2*10^-10 for [H3O+] and 3.125*10^-5 for [OH-] for 9.5

c. what is the [OH-] in each?
I got 3.2*10^-8 for [H3O+] and 3.125*10^-7 for [OH-] for 7.5.
Thank you so much!

• Chem -

It strikes me as odd that you round 3.162 to 3.2 but you carry 3.125 to many more places.I think you rounded too quickly (or too much) for d. If you had made that 3.16E-7 instead of 3.2, then the OH would have been 3.16E-8.

Second set.
b. same problem. 3.2 should be 3.16 and that changes the OH.
c. same problem. 3.2 should be 3.16 and that changes the OH.