Potassium hydrogen phthalate

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Potassium hydrogen phthalate
Potassium hydrogen phthalate bottle sample.jpg
Potassium hydrogen phthalate sample
Names
IUPAC name
Potassium hydrogen phthalate
Other names
1,2-Benzenedicarboxylic acid
Hydrogen potassium phthalate
KHP
KHPh
Monopotassium phthalate
Phthalic acid potassium salt
Potassium acid phthalate
Potassium biphthalate
Potassium biphthalate monopotassium salt
Properties
C8H5KO4
Molar mass 204.22 g/mol
Appearance White solid
Odor Odorless
Density 1.636 g/cm3
Melting point 295–300 °C (563–572 °F; 568–573 K) (decomposes)
Boiling point Decomposes
8 g/100 ml (20 °C)
Solubility Slightly soluble in ethanol, methanol
Insoluble in hydrocarbons, halocarbons
Vapor pressure ~0 mmHg
Hazards
Safety data sheet Sigma-Aldrich
Flash point Non-flammable
Lethal dose or concentration (LD, LC):
3,200 mg/kg (rat, oral)
Related compounds
Related compounds
Phthalic acid
Phthalic anhydride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Potassium hydrogen phthalate or potassium biphthalate, often called simply KHP, is an acidic salt of phthalic acid. KHP has the chemical formula C8H5KO4.

Properties

Chemical

Potassium hydrogen phthalate is neutralized completely with potassium hydroxide or carbonate to dipotassium phthalate.

Physical

Potassium hydrogen phthalate is a colorless crystalline solid, moderate soluble in water. It is stable in air and is not hygroscopic.

Availability

Potassium hydrogen phthalate is sold by chemical suppliers.

Preparation

Can be prepared by partially neutralizing phthalic acid with potassium hydroxide or potassium bicarbonate.

Projects

  • Standard in acid-base titrations and thermogravimetric analysis
  • Buffering agent

Handling

Safety

Potassium hydrogen phthalate is irritant and should be handled with care.

Storage

In closed bottles.

Disposal

No special disposal is required, though it's best to neutralize it completely before disposal.

References

Relevant Sciencemadness threads