Answer:
6.5x10⁻³M = [OH⁻]
Explanation:
The Kb of a Weak base as ethylamine is expressed as follows:
Kb = [OH⁻] [C₂H₅NH₃⁺] / [C₂H₅NH₂]
As the equilibrium of ethylenamine is:
C₂H₅NH₂(aq) + H₂O(l) ⇄ C₂H₅NH₃⁺(aq) + OH(aq)
The concentration of C₂H₅NH₃⁺(aq) + OH(aq) is the same because both ions comes from the same equilibrium. Thus, we can write:
Kb = [OH⁻] [C₂H₅NH₃⁺] / [C₂H₅NH₂]
6.4x10⁻⁴ = [X] [X] / [C₂H₅NH₂]
Also, we can assume the concentration of ethylamine doesn't decrease. Replacing:
6.4x10⁻⁴ = [X] [X] / [0.066M]
4.224x10⁻⁵ = X²
6.5x10⁻³M = X
<h3>6.5x10⁻³M = [OH⁻]</h3>
D because as he walks away the radio will get louder
<span>Most fertilizer bags are marked with three numbers, which represent the amounts of the following chemicals: nitrogen, phosphorus, and potassium. The third number represents the amount of potassium in the fertilizer. All three of these chemicals are important for plants, but different plants require different amounts of these chemicals, so the label helps consumers determine which product to buy.</span>
The answer would be D because from my research it's the only one that didn't have a catalyst
AND OCYGENAND OXYGEN!!
** hope this helps
