Why is KHP commonly used in standardizing basic solutions?

Why is KHP commonly used in standardizing basic solutions?

This is because NaOH is very hygroscopic. KHP is commonly used as a primary standard because it is a solid at room temperature, is stable in air, and is not hygroscopic, which makes it possible to accurately determine the mass of KHP using a balance.

Is KHP primary standard solution?

A sodium hydroxide solution of approximate concentration (0.2 M) is to be prepared. It is then standardized by titrating it against an accurately weighed sample of potassium acid phthalate (KHP), HOOC-C6H4-COOK , which is a primary standard acidic substance.

Why do you need to use KHP to standardize a solution of NaOH?

But when it comes to anything analytical where you start to involve calculations, standardization is a must. This is done with NaOH because it’s hygroscopic and readily sucks up the moisture in the air. So what is being weighed isn’t totally NaOH, but also the moisture that it has absorbed.

What primary standard will be used to standardize the NaOH solution in this lab?

In the first part of this lab. you will standardize a sodium hydroxide solution by titrating it with a primary standard, KHP (potassium hydrogen phthalate see reverse) .

What characteristics of KHP makes it appropriate for standardization?

Potassium hydrogen phthalate makes for a good primary standard because it is stable, high in purity, non-hydroscopic, highly soluble, non-toxic, high in molecular weight, cheap, and available.

Is phenolphthalein a primary standard?

The amount of an acid (or a base), which is exactly equivalent chemically to the amount of some standard base (or an acid), is determined by an acid-base titration….Colour changes of indicators with pH.

Is KHP a secondary standard?

Potassium Hydrogen Phthalate (KHP) is a classic primary standard substance in that it is readily available in high purity; is relatively inexpensive; is easy to dry; is neither hygroscopic, oxidized by air, nor affected by Carbon Dioxide (thus making it easy to weigh out); does not undergo decomposition during storage; …

What is the purpose of phenolphthalein?

Phenolphthalein is often used as an indicator in acid–base titrations. For this application, it turns colorless in acidic solutions and pink in basic solutions. It belongs to the class of dyes known as phthalein dyes.

Why is sodium hydroxide not a good primary standard?

NaOH has no criteria given above. It is not suitable for the primary standards because they absorb the moisture from the atmosphere. It also absorbs carbon dioxide from the atmosphere. Hence, NaOH is not a primary standard because it has no quality of primary standard.

Why NaOH is not a primary standard?

Is benzoic acid a primary standard?

Some examples of primary standards for titration of solutions, based on their high purity, are provided: Benzoic acid for standardisation of waterless basic solutions: ethanolic sodium and potassium hydroxide, TBAH, and alkali methanolates in methanol, isopropanol, or DMF.

Why is potassium permanganate not a primary standard?

KMnO4 is not used as primary standard because it is difficult to obtain the pure state of KMnO4 as it is not free from MnO2. Also, the colour is so intense that it acts as its own indicator.

What is KHP and how is it used?

RICCA CHEMICAL COMPANY uses large quantities of KHP in the manufacture and quality control of its products. KHP is used in the manufacture of buffers, organic carbon standards, acidimetric standards and other products.

What are primary primary standards used for?

Primary standards are typically used in titration to determine an unknown concentration and in other analytical chemistry techniques. Titration is a process in which small amounts of a reagent are added to a solution until a chemical reaction occurs.

What is the use of KHP in acidimetric reactions?

KHP is used in the manufacture of buffers, organic carbon standards, acidimetric standards and other products. It is also used in the quality control of Potassium Hydroxide and Sodium Hydroxide solutions, and in the standardization of Perchloric Acid in Glacial Acetic Acid. A typical acidimetric reaction is:

How do you find the concentration of NaOH in KHP solution?

To check the concentration of NaOH, a chemist must titrate a primary standard—in this case, a solution of potassium hydrogen phthalate (KHP). KHP does not absorb water or carbon dioxide, and it can provide visual confirmation that a 1-gram solution of NaOH really contains 1 gram. There are many examples of primary standards.