Answer:
![[base]=0.28M](https://tex.z-dn.net/?f=%5Bbase%5D%3D0.28M)
Explanation:
Hello,
In this case, by using the Henderson-Hasselbach equation one can compute the concentration of acetate, which acts as the base, as shown below:
![pH=pKa+log(\frac{[base]}{[acid]} )\\\\\frac{[base]}{[acid]}=10^{pH-pKa}\\\\\frac{[base]}{[acid]}=10^{4.9-4.76}\\\\\frac{[base]}{[acid]}=1.38\\\\](https://tex.z-dn.net/?f=pH%3DpKa%2Blog%28%5Cfrac%7B%5Bbase%5D%7D%7B%5Bacid%5D%7D%20%29%5C%5C%5C%5C%5Cfrac%7B%5Bbase%5D%7D%7B%5Bacid%5D%7D%3D10%5E%7BpH-pKa%7D%5C%5C%5C%5C%5Cfrac%7B%5Bbase%5D%7D%7B%5Bacid%5D%7D%3D10%5E%7B4.9-4.76%7D%5C%5C%5C%5C%5Cfrac%7B%5Bbase%5D%7D%7B%5Bacid%5D%7D%3D1.38%5C%5C%5C%5C)
![[base]=1.38[acid]=1.38*0.20M=0.28M](https://tex.z-dn.net/?f=%5Bbase%5D%3D1.38%5Bacid%5D%3D1.38%2A0.20M%3D0.28M)
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Answer: Mutations can cause instant adaptations, while natural selection is the process by which adaptations occurs over a series of generations. Adaptations are changes or processes of changes by which an organism or species becomes better suited for its environment. A mutation is an alteration of the DNA sequence.
(4) total number of valence electrons, because they exist in the same group.
Answer:

Explanation:
Given
The data in the table
Required
Follow the steps appended to the question;
Step 1: Calculate the Mean or Average
Mean = Summation of lengths divided by number of teams;



Step 2: Get The Range



Step 3: Divide Range by 2



Step 4: Determine the Precision

Substitute 2.70 for Average and 0.1 for Approximate Range

Answer: A persistent or non-volatile chemical agent can remain on a surface for more than 24 hours.
Explanation:
Non-volatile substance is defined as the one which does not readily evaporate into its surrounding. Generally, a non-volatile substance has strong intermolecular forces between its molecules.
A non-volatile substance will take more than 24 hours to remain on the surface.
On the other hand, a substance with weak intermolecular forces present in its molecules will readily evaporate into the atmosphere.
For example, acetic acid is a volatile substance and quickly evaporates into the atmosphere.
Thus, we can conclude that a persistent or non-volatile chemical agent can remain on a surface for more than 24 hours.