Why is the amount of CaCO3 in antacid not estimated by direct titration?

Why is the amount of CaCO3 in antacid not estimated by direct titration? – Quora. Calcium carbonate is insoluble in water . Whether it is in an antacid or merely as a CaCO3 sample you cannot carry out a direct titration . The rate of reaction between the acid ( say dilute HCl) and CaCO3 is slow.

How do you find the percentage of calcium carbonate in limestone?

You take the atomic mass of calcium over the atomic mass of CaCO3 and multiply it by 100 to get the percentage. is 47.997 g ( 15.999 g×3 ).

What is the percentage of calcium carbonate in chalk?

Chalk is composed of the shells of such minute marine organisms as foraminifera, coccoliths, and rhabdoliths. The purest varieties contain up to 99 percent calcium carbonate in the form of the mineral calcite.

How do you calculate the amount of acid reacted or neutralized by the antacid?

Therefore, the number of moles of HCl that reacted with the antacid should be equal to the total number of moles of HCl minus the number of moles of excess HCl. Take this amount and divide by the mass of the sample and you have your acid neutralizing capacity.

What is the percentage of calcium in limestone?

Three of the limestones compare favorably with the highest grade of high-calcium limestones being used at the present time; the average calcium (plus magnesium) carbonate content is 98.5 percent (the range is 97.7 to 99.1 percent).

How do you calculate the percentage of calcium carbonate?

So the mass percentage of calcium in calcium carbonate is 40.078 divided by 100.086 all multiplied by 100 percent. This gives a value of about 40 percent. The mass percentage for carbon is 12.011 divided by 100.086 multiplied by 100 percent which gives us a value of about 12 percent.

What method of titration is used to determine calcium content of a sample?

complexometric titration
This method, called a complexometric titration, is used to find the calcium content of milk, the ‘hardness’ of water and the amount of calcium carbonate in various solid materials. The method uses a very large molecule called EDTA which forms a complex with calcium ions.

How do you find the percentage of calcium carbonate in chalk?

A titration is then carried to determine the concentration of the excess hydrochloric acid in the flask. Knowing the excess and the original amount of acid we can work back (hence back titration) to find the amount of acid reacting with the calcium carbonate in the chalk and hence the percentage of calcium carbonate in the chalk.

How do you titrate chalk?

The approach is known as a back titration. A measured mass of chalk from the cliff is weighed out and then dissolved completely in an excess of hydrochloric acid. The resultant solution is made up to the mark in a 250ml volumetric flask. A titration is then carried to determine the concentration of the excess hydrochloric acid in the flask.

How do you titrate calcium carbonate and hydrochloric acid?

Calcium carbonate is an insoluble base so it will combine with a strong acid such as hydrochloric acid forming soluble calcium chloride solution and water and carbon dioxide. Here is the equation: CaCO3 (s) + 2HCl (aq) = CaCl2 (aq) + H2O(l) + CO2 (g) The approach is known as a back titration.

How to find the percent of calcium carbonate in commercial antacids?

Finding the percent of calcium carbonate in commercial antacid by using back titration. The reaction between CaCO3 and HCl is as follows:CaCO3 + 2HCl –> CaCl2 + CO2 +H2O Therefore, molar ratio between CaCO3 and HCl is 1:2. 0.042 moles HCl reacted, therefore 0.021 mol CaCO3 were present in the sample.