Statement (I) is correct as potassium hydrogen phthalate serves as a reliable primary standard due to its stable and non-hygroscopic properties.
Statement (II) is also correct as phenolphthalein is a suitable indicator for acid-base titrations, exhibiting a color change in the pH range of 8.3 to 10.1.
List I-Buffers | List II-pH Value | ||
A | HCl and KCl | I | 8 to 10 |
B | HCl and Potassium Hydrogen Phthalate | II | 2.2 to 4.0 |
C | NaOH and Potassium Hydrogen Phthalate | III | 1.2 to 2.2 |
D | H3BO3, NaOH, and KCl | IV | 4.2 to 5.8 |