the equilibrium constant expression for the ionization of HOBr in water, then calculate
the concentration of HOBr(aq) in an HOBr solution that has [H+] equal to 1.8 10–5 M.
The equilibrium constant expression for the ionization of HOBr in water is:
K = [H+][OBr-]/[HOBr]
We are given that [H+] = 1.8 10–5 M. We need to find the concentration of HOBr(aq), which we can do by rearranging the equilibrium constant expression:
[HOBr] = [H+][OBr-]/K
We need the value of K for this calculation. The ionization of HOBr is an acid-base reaction, and the acid dissociation constant (Ka) can be used as a substitute for K. The expression for Ka is:
Ka = [H+][OBr-]/[HOBr]
The relationship between Ka and K is:
K = Kw/Ka
where Kw is the ion product constant for water, which is 1.0 10-14 at 25°C. Therefore, we can calculate K as:
K = 1.0 10-14 / Ka
The value of Ka for HOBr can be found in a reference source or calculated using the equilibrium concentrations of HOBr, H+, and OBr-. For simplicity, we will assume that the value of Ka for HOBr is 2.3 10-9 at 25°C.
Using this value for Ka, we can calculate K:
K = 1.0 10-14 / 2.3 10-9 = 4.3 10-6
Now we can use the equation we derived earlier to find the concentration of HOBr:
[HOBr] = [H+][OBr-]/K
We are given that [H+] = 1.8 10–5 M. We need to find [OBr-], which we know is equal to [HOBr] because the solution is neutral (the concentrations of H+ and OH- are equal). Therefore:
[HOBr] = [OBr-] = 1.8 10–5 M
[Answer: The concentration of HOBr(aq) in an HOBr solution that has [H+] equal to 1.8 10–5 M is 1.8 10–5 M.]
The ionization of HOBr in water can be represented by the following equation:
HOBr(aq) ⇌ H+(aq) + OBr-(aq)
The equilibrium constant expression for this reaction can be written as:
K = [H+(aq)] * [OBr-(aq)] / [HOBr(aq)]
Given that [H+] is equal to 1.8 × 10⁻⁵ M, we can substitute this value into the equilibrium constant expression:
K = (1.8 × 10⁻⁵) * [OBr-(aq)] / [HOBr(aq)]
Since the equilibrium constant is a constant value at a given temperature, we need more information to determine the specific value of K.
If the value of K is given, we can rearrange the equation to solve for the concentration of HOBr(aq):
[HOBr(aq)] = (1.8 × 10⁻⁵) * [OBr-(aq)] / K
However, if the value of K is not provided, we cannot solve for the concentration of HOBr(aq) without additional information.