0.1 mol of HCl is added to 1 L of water. What is [H+] and [OH-]?
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To find the concentrations of [H+] and [OH-] in a solution of HCl, we need to consider the ionization of HCl in water. HCl dissociates completely in water to form H+ and Cl- ions.
The balanced equation for the dissociation of HCl in water is:
HCl(aq) → H+(aq) + Cl-(aq)
Since the stoichiometry of the reaction shows that 1 mole of HCl produces 1 mole of H+, the concentration of H+ in the solution will be equal to the concentration of HCl.
Given that 0.1 mol of HCl is added to 1 L of water, the concentration of H+ is 0.1 mol/L.
Now, to determine the concentration of OH-, we need to remember that in pure water at 25°C, the concentration of [H+] equals the concentration of [OH-], which is 1 x 10^-7 M.
However, when an acid such as HCl is added, it reacts with water and increases the concentration of H+ ions. This results in a decrease in the concentration of OH- ions.
Since we have an excess of H+ ions from the dissociation of HCl, we can assume that nearly all the OH- ions in the water are consumed to neutralize the added H+ ions.
Thus, the concentration of OH- ions can be considered negligible compared to the concentration of H+ ions in this case.
HCl ionizes completely; therefore, (H^+) = 0.1 mol/L.
Calculate OH from (H^+)(OH^-) = Kw = 1E-14