A buffer solution is prepared by adding NaC2H2O2 to a solution of HC2H2O2 (acetic acid). HC2H3O2(aq) = H+ (aq) + C2H302 - (aq) What happens if KCl is added

pH is not been modified. No changes.

Explanation:

Our buffer is made of acetic acid, a weak one and the salt from its conjugate base, sodium acetate.

NaC₂H₃O₂ → Na⁺   +  C₂H₃O₂⁻

The acetate anion can make hydrolisis in water to produce acetic acid again.

C₂H₃O₂⁻  + H₂O  ⇄  C₂H₃O₂H + OH⁻     Kb

KCl is neutral salt. When we dissociate it:

KCl → K⁺  +  Cl⁻

Both ions come from a strong base and a strong acid. They won't make hydrolisis in water because they are conjugate weak acid and base

K⁺ + H₂O ← KOH + H⁺

Cl⁻ + H₂O ← HCl + OH⁻

These reactions can't be possible.

That's why it doesn't occur anything in our buffer, this salt does not give OH⁻ or H⁺ to medium to modify pH

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

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~ trueboss72