Ionic Equilibrium Part 1

In the titration of strong acid with the weak base methyl orange is an suitable indicator. Initially, $\mathrm{pH}$ of weak base is high, as acid is added pH falls slowly and equivalence point is attained. (Equivalence point is point when chemical equivalentquantities of acid and base are mixed). After equivalence point $\mathrm{pH}$ falls sharply. So, methyl orange having $\mathrm{pH}$ range $3.2-4.4$ will work as suitable indicator. Methyl orange shows red colour in acidic medium and yellow colour in basic medium. Hence, statement I is true. In titration of weak acid and strong base initially $\mathrm{pH}$ of weak acid is below 7. As strong base is added $\mathrm{pH}$ increases slowly and equivalence point is attained. After equivalence point $\mathrm{pH}$ abruptly increases. So, phenolphthalein having $\mathrm{pH}$ range $8.2-10.0$ will work as suitable indicator. Phenolphthalein is colourless in acidic solution whereas pink in basic solution. Hence, statement II is false.