When a weak acid ( HA ) is titrated with a strong base, such as NaOH what species are decreasing in concentration before the equivalence point is reached? Na + Na + and A − A − HA HA and H + H + ( H 3 O + ) ( H 3 O + ) Na + Na + and OH − OH − HA HA and A − A −

HA and A-

Explanation:

before the equivalence point, there is a HA/A- buffer solution by wich the pH is calculated.

Therefore, the species that decrease their concentration before the equivalence point are HA and A-

the formula mass of a molecule or a compound is the sum of the atomic weights of the atoms in its empirical formula

(that's what i know about formula mass)

c

explanation: