Potassium hydrogen phthalate (KHP) is a suitable primary standard because it is stable in solid form and in solution, it is soluble in water, it is not hygroscopic, it dries easily and its molecular weight (about 200 g mol1) gives practical results and precise masses of the Fabric for manufacturingAlso note why NaOH is not used as the primary standard?
a) Absorb moisture from the air. NaOH NaOH NaOH is not suitable as a primary standard because it readily absorbs moisture, H2O H_2O H2O, from the atmosphere. They easily absorb carbon dioxide from the atmosphere.
It is used to determine the concentration of the base. We know the molar mass of the samples and also the weight of KHP.
There are many examples of primary standards. Sodium chloride (NaCl), used as the primary standard for reactions with silver nitrate (AgNO3). Powdered zinc which, after being dissolved in hydrochloric or sulfuric acid, can be used to standardize solutions of EDTA (ethylenediaminetetraacetic acid).
Potassium dichromate (K2Cr2O7) is suitable as the primary standard. It cannot be obtained in a very pure form. It reacts easily with traces of organic substances or other reducing agents present in the water. It decomposes in the presence of the sun.
Due to its intense color, the ion acts as its own indicator, so there is no need to add an indicator that is normally required. Potassium permanganate is not a primary standard and the preparation of the solution always leads to the formation of solid manganese dioxide (MnO2).
Answer: There are three main reasons why HCl is not suitable as a primary standard: HCl is not a solid at ambient temperature and pressure. HCl cannot be obtained with a very high degree of purity. HCl does not have a high molecular weight.
Introduction: Pure Sodium Carbonate is a non-hygroscopic primary standard reagent. A standard solution obtained by dissolving a known quantity of solid Na2CO3 in a fixed volume can be used to standardize other acid solutions.
A substance is classified as a primary standard if it exhibits the following properties: (i) it is readily available in high purity. Substances whose standard solutions cannot be prepared directly are called secondary standards. For example KMnO4, NaOH, KOH etc.
Hydrochloric acid, HCl and sulfuric acid, H2SO4, are NOT suitable as primary standards because they are both commercially available as easily dilutable concentrated solutions, but the concentration of the concentrated solution is NOT known.
First, solid NaOH absorbs water from the air, making it impossible to accurately weigh a sample while preparing the solution. Second, a NaOH solution tends to absorb atmospheric carbon dioxide, which is slightly acidic.
Sometimes it is necessary to standardize the solutions (reagents) before starting the chemical experiments as this allows us to get correct readings during the experiment while the exact concentration of the solution can be different.
To standardize NaOH, first pipette 10.0 mL of 0.1 N hydrochloric acid (HCl) into a vial. Add about 50ml of water (remember, not tap water) and three drops of methyl red indicator. Fill a 25 mL cage with 0.1 N sodium hydroxide solution and note the initial volume.
To standardize a basic solution such as NaOH, an acid is required whose quantity can be determined with high precision (a so-called primary standard). Potassium acid phthalate (KHP), a monoprotic acid, is often used as the primary standard for titration bases. KHP can be oven dried to remove traces of water.
The determination of titration or normalization of a volumetric solution used for titration is one of the most important prerequisites for reliable and transparent titration results. The nominal concentration of a volumetric solution used as a titrant in the titration process is known.
Potassium hydrogen phthalate, often referred to as KHP, is an acidic saline compound. KHP is slightly acidic and is often used as the primary standard for acid-base titrations because it is solid and stable in air, making it easy to accurately weigh. It is not hygroscopic.
The phenolphthalein indicator is most commonly used in assays that use KHP as an acidimetric standard to standardize basic solutions. Potassium acid phthalate.