Physical property is C.Density
They trend to lose elections and become anions
Phosphoric acid. Also known as orthophosphoric acid in or phosphoric(V) acid, is a weak acid with the chemical formula H3PO4. The pure compound is a colorless solid.
Answer is: because pH value of solution is changing.
Balanced chemical reaction: NaOH(aq) + HCl(aq) → NaCl(aq) + H₂O(l).
pH of sodium hydroxide solution is above seven (basic), when solution of hydrochloric acid is added, pH slowly dropping until it became neutral solution (pH is equal seven) and that is endpoint of titration.
Salt and water are formed
H₃PO₄ + 3KOH = K₃PO₄ + 3H₂O
CH₃COOH + NaOH = CH₃COONa + H₂O