Final answer:
The concentration of hydroxide ions [OH-] in a solution where 3.00×10−3 mol of HBr is dissolved in 13.0 L of water is 4.33×10−12 M at 25°C.
Step-by-step explanation:
To calculate the concentration of hydroxide ions ([OH−]) when 3.00×10−3 mol of HBr are dissolved in water to make 13.0 L of solution, we first need to determine the concentration of hydronium ions ([H3O+]).
Since HBr is a strong acid, it will dissociate completely in water.
The moles of HBr will equal the moles of [H3O+], which is 3.00×10−3 mol. The concentration of [H3O+] is therefore 3.00×10−3 mol / 13.0 L = 2.31×10∔ M.
At 25 °C, the product of [H3O+] and [OH−] is always 1.0×10∑4 M2 (the ion product of water). We can use this relationship to find [OH−]:
[OH−] = 1.0×10∑4 M2 / [H3O+] = 1.0×10∑4 M2 / 2.31×10∔ M = 4.33×10−12 M
Therefore, the concentration of hydroxide ions in the solution is 4.33×10−12 M. Express your answer with the appropriate units.