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NIST185I

Potassium hydrogen phthalate

NIST® SRM® 185i, pH standard

Synonym(s):

Potassium phthalate monobasic, KHP, Phthalic acid monopotassium salt, Potassium biphthalate, Potassium hydrogen phthalate

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About This Item

Linear Formula:
HOOCC6H4COOK
CAS Number:
877-24-7
Molecular Weight:
204.22
UNSPSC Code:
41116107
NACRES:
NA.24
PubChem Substance ID:
329818718
MDL number:
MFCD00013070
Beilstein/REAXYS Number:
3637128
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grade

certified reference material

Quality Segment

100

agency

suitable for SM 2310, suitable for SM 2320

form

crystals

packaging

pkg of 60 g

manufacturer/tradename

NIST®

mp

295-300 °C (dec.) (lit.)

SMILES string

[K+].OC(=O)c1ccccc1C([O-])=O

InChI

1S/C8H6O4.K/c9-7(10)5-3-1-2-4-6(5)8(11)12;/h1-4H,(H,9,10)(H,11,12);/q;+1/p-1

InChI key

IWZKICVEHNUQTL-UHFFFAOYSA-M

General description

SRM 185I is certified as a pH standard [pH(S)].   

Each unit of SRM 185I consists of 60 g of potassium hydrogen phthalate.

SRM 185I _SDS

SRM 185I _CoA

Application

Potassium hydrogen phthalate standard reference material (SRM) is intended for use in preparing solutions for calibrating electrodes for pH measuring systems.

Features and Benefits

  • SRM 185I is available with certified pH(S) values and their expanded uncertainties. 
  • Certified values are derived from potential measurements of cells without liquid junction by the primary measurement method. 
  • Certified values are metrologically traceable to the International System of Units (SI) of amount-of-substance and mass and to the definition of single ion activity. 
  • The NIST certificate is provided with maintenance, storage, handling, and use instructions.

Other Notes

Please download a current certificate at nist.gov/SRM for current analytes and certified values.

Legal Information

NIST is a registered trademark of National Institute of Standards and Technology
SRM is a registered trademark of National Institute of Standards and Technology

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Storage Class

11 - Combustible Solids

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