Protons, the number of protons cannot change or the element will change as well.
it's Lithium or Li
..............................
KOH added : 7.5 ml
<h3>Further explanation</h3>
Buffer solution of weak acid HCOOH and strong base KOH
Reaction
initial = 100 ml 0.1 M HCOOH = 10 ml mol HCOOH, and x mlmol of KOH
KOH + HCOOH ⇒ COOHK + H₂O
x 10
x x x x
- 10-x x x
[HCOO - ] = 3[HCOOH]
