The compound that changes color when exposed to basic solutions is an indicator. Adding color indicators to the reaction mixture can help to identify the titration endpoint.
Tarpachite is another name for Potassium chromate K2CrO4 and is a yellow orthorhombic or hexagonal crystal that can be found at room temperature. The yellow compound that comes in powder form is insoluble in alcohol and ether, which makes it a yellow compound in water.
Most of us know that a potassium chromate test is the most widely used method for detecting urine ketone. Although it has been used for decades how it works is still not clear to scientists.
The potassium chromate indicator is an easy method to determine the presence of ketones in the urine, but unfortunately, it is also very toxic and dangerous to use. But it’s still the only method to detect ketones in the urine.
This is a great method to determine the presence of ketones in the blood and in the urine. The method is simple, cheap and the preparation process is easy.
How to prepare potassium chromate indicator?
K2CrO4 is used as an indicator in the detection of chloride. The precipitation titration method is also known as the Moore (Mohr) method. The endpoint is the change in color from yellow to brown.
- Put 05.00gm of potassium chromate into a volumetric flask of distilled water and swirl it until it completely dissolved. After this dilute to 100 ml with distilled water
- Once it is dissolved, dilute to 100.00 ml with distilled water.
Potassium chromate with pKa value of -6.2 is the most commonly used indicator in the determination of chloride by titration with standard silver nitrate solution.
When Cl- or Br- ions coexist, the potassium chromate indicator method can only be used for direct titrations. The iodide ion and the thiocyanate ion cannot be determined with this method.
The potassium chromate indicator method can only be used for direct titrations when the two ion species coexist. For example when cl- or Br- coexist. The thiocyanate ion and the iodide ion cannot be determined using this method.