Answer:
pKa = 4.89.
Explanation:
We can solve this problem by using the <em>Henderson-Hasselbach equation</em>, which states:
pH = pKa + log ![\frac{[A^-]}{[HA]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
In this case [A⁻] is the concentration of sodium benzoate and [HA] is the concentration of benzoic acid.
We <u>input the given data</u>:
4.63 = pKa + log 
And <u>solve for pKa</u>:
pKa = 4.89
Answer:
11812.58 meters = 11.81258 Km
Explanation:
hope that helps
the answer is b
The posterior pituitary secretes two important endocrine hormones—oxytocin and antidiuretic hormone