Phase 3 is the integration phrase
Answer:
1.41 × 10⁻¹⁰ M
Explanation:
We have a solution with a pH of 9.85 at 25 °C. We can calculate the concentration of H⁺ using the following expression.
pH = -log [H⁺]
[H⁺] = antilog -pH
[H⁺] = antilog -9.85
[H⁺] = 1.41 × 10⁻¹⁰ M
H⁺ is usually associated with water molecules forming hydronium ions.
H⁺ + H₂O → H₃O⁺
Then, the concentration of H₃O⁺ ions is 1.41 × 10⁻¹⁰ M.
We can calculate how long the decay by using the half-life equation. It is expressed as:
A = Ao e^-kt
<span>where A is the amount left at t years, Ao is the initial concentration, and k is a constant.
</span><span>From the half-life data, we can calculate for k.
</span>
1/2(Ao) = Ao e^-k(30)
<span>k = 0.023
</span>
0.04Ao = Ao e^0.023(t)
<span>t = 140 sec</span>
