Question

Va rog ajutatima ca 1 si 2.
1)Calcuati concentratia ionilor H3O+, la 25°C in solutiile:
a) [HO-] = 2*10^-9 M
d) [H3O+] = [HO-]
c) [HO-] = 10^3 *[H3O+]
2)Calculati [H3O+], [HO-], [NO3-] la 25°C,in solutie apoasa de HNO3 0,15M.

Answer 1

a) [H3O+] = 10^-14/2×10^-9 = 5×10^-6M

b) [H3O+] = [OH-] = 10^-7 M

c) [OH-] = 10^3×[H3O+]

[H3O+]×[OH-] = 10^-14 => [H3O+]+10^3×[H3O+> = 10^-14 => [H3O+]^2 = 10^-14/10^3 = 10^-17 => [H3O+] = 10^-8,5M

2) HNO3 - A.T => [HNO3] = C = [H3O+] = 0,15M

[OH-] = 10^-14/15×10^-2 = 6,66×10^-14M