Answer to Question #330575 in General Chemistry for Ivan Ackerman

Question

Calculate the hydronium ion, H3O+ , and hydroxide ion, OH− , concentrations for a 0.0111 M HCl solution.

[H3O+]=

[OH−]= 

Answer 1

Solution:

HCl is a strong acid that completely dissociates into hydronium (H₃O⁺) and chloride (Cl⁻) ions.

The dissociation equation for HCl in aqueous solution is:

HCl(aq) + H₂O(l) → H₃O⁺(aq) + Cl⁻(aq)

From the reaction, one hydronium ion and one chloride ions are formed.

So, the concentration of H₃O⁺ is same as the concentration of HCl.

Therefore,

[H₃O⁺] = 0.0111 M

K_w = [H₃O⁺] × [OH⁻] = 1.0×10⁻¹⁴

Therefore,

[OH⁻] = K_w / [H₃O⁺] = (1.0×10⁻¹⁴) / (0.0111) = 9.01×10⁻¹³

[OH⁻] = 9.01×10⁻¹³ M

Answer:

[H₃O⁺] = 0.0111 M

[OH⁻] = 9.01×10⁻¹³ M