Answer:
The pH of the buffer is 4.77
Explanation:
Using Henderson-Hasselbalch equation we can solve the pH of the buffer:
pH = pKa + log [A⁻] / [HA]
<em>Where pH is the pH of the buffer</em>
<em>pKa is -log Ka = 5.056</em>
<em>[A⁻] = [NaA] = 0.2M</em>
<em>[HA] = 0.39M</em>
<em />
Replacing:
pH = 5.056+ log [0.2] / [0.39]
pH = 4.77
<h3>The pH of the buffer is 4.77</h3>
<em />
The (2) calcium atom, because when looking at the periodic table, we see that the calcium atom is in a location where according to the periodic table, has the lower electronegativities in respect to the other three choices. We see that it also has a lower electronegativity value than the others. Electronegativity is the attraction constant for the electrons in a chemical bond. The higher the electronegativity, the higher the attraction of the electrons. Fluorine has the highest electronegativity with 4.0.