Answer:
Valence electrons are the most important electrons to an atom.
Explanation:
They will determine many of the atoms traits since they are involved in bonding with other atoms.
I think c cause if he is in a relationship that’s abusive he needs to speak up before it goes way worst.
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>
Answer:
Increasing precision with multiple measurements
Explanation:
The more measurements you take (provided there is no problem with the clock!), the better your estimate will be. Taking multiple measurements also allows you to better estimate the uncertainty in your measurements by checking how reproducible the measurements are.
