Calculate the [H3O+] of solutions a and b; calculate the [OH-] solutions c and d.

9. pH = 2.76

10. pH = 3.65

11. pOH = 3.65

12. POH = 6.87

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Explanation:

9.) 10-2.76 = 0.0174  [H30+] = 1.74*10-3 M

10.) 10-3.65=0.00224  [H3O+] = 2.24*10-2 M

11.) 10-3.65=0.00224 [OH-] = 2.224*10-4M

12.) 10-6.87=0.00000135  [OH-] = 1.35*10-7M