Question

calculate the value of [-OH] from the given [H3O+] in each solution and label the solution as acidic or basic:

a) [H3O+]=6.5×10 (negative 10 power)M

b) "          "=8.6×10 (negative 3rd power)M

Answer 1

Answer:

H₂O + H⁺ H₃O⁺

That means the hydronium ion H₃O⁺ is the Acdic in nature.

a) 6.5 x 10^-10

That means it is the concentration of H⁺ ions.

P^H = -log₁₀[H⁺]

P^H = -log₁₀[6.5 x 10^-10]

P^H = 10 - log 6.5

P^H = 10 - 0.8129

P^H = 9.187

If P^H = 7, Then the compound is the neutral. But here the PH value is more than 7. Hence th compound is Basic in nature.

[^-OH] caluculation:

P^H + P^OH = 14

P^OH = 14 - P^H

P^OH = 14 - 9.187

P^OH = 4.813

P^OH = -log₁₀ [^-OH]

4.183 = -log₁₀ [^-OH]

[-OH] = 10^-4.187

[-OH] = 0.153 x 10^-5

b) 8.6 x 10^-3

That means it is the concentration of H⁺ ions.

P^H = -log₁₀[H⁺]

P^H = -log₁₀[8.6 x 10^-3]

P^H = 3 - log 8.6

P^H = 3 - 0.934

P^H = 2.066

If P^H = 7, Then the compound is the neutral. But here the PH value is less than 7. Hence th compound is Acidic in nature.

[^-OH] caluculation:

P^H + P^OH = 14

P^OH = 14 - P^H

P^OH = 14 - 2.066

P^OH = 11.934

P^OH = -log₁₀ [^-OH]

11.934 = -log₁₀ [^-OH]

[-OH] = 10^-11.934

[-OH] = 1.164 x 10^-12