Double Titration

Double titration is a laboratory technique that is used to determine the concentration of an unknown substance in a sample. This technique involves two steps: the first step is to titrate the sample with a standard solution to determine the concentration of the standard solution, and the second step is to titrate the sample with another standard solution to determine the concentration of the unknown substance. In this blog post, we will discuss double titration experiments and provide examples of how this technique can be used in a laboratory setting.

Meaning of Double Titration:

The process of titration can be defined as a method in which the concentration of an unknown substance is determined by reacting it with a known concentration of another substance. In a double titration, two different solutions are used to find the concentration of an unknown solution. It is also known as indirect titration.

Double Titration Application in the Analysis of Commercial Antacid Tablets

One common example of double titration is acid-base titration. This type of titration is used to determine the concentration of an acid or base in a solution. The most common acid-base titrations are those between hydrochloric acid and sodium hydroxide and between sulfuric acid and sodium hydroxide.

In a double titration, two reagents are used to determine the concentration of an unknown solution. The first reagent is used to standardise the second reagent. The second reagent is then used to determine the concentration of the unknown solution. The double titration method is often used in the analysis of commercial antacid tablets.

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Double Titration Experiment Procedure:

-Take two clean, dry beakers and label one ‘A’ and the other ‘B.’

-Pour 50 mL of DI water into each beaker.

-Add two scoops of sodium carbonate to beaker ‘A’ and stir until it is completely dissolved.

-Add two scoops of calcium chloride to beaker ‘B’ and stir until it is completely dissolved.

-Using a graduated cylinder, add 20 ml of the sodium carbonate solution from beaker ‘A’ to beaker ‘B.’

-Stir the contents of beaker ‘B’ until the solutions are mixed.

-Using a pH metre, take a reading of the pH of the solution in beaker ‘B.’

-Repeat Steps # five through seven, adding 20 mL of the calcium chloride solution from beaker ‘B’ to beaker ‘A’ this time.

-Take a pH reading of the solution in beaker ‘A.’

The point of the double titration is to find the exact point at which the acid and base solutions neutralise each other. This is done by slowly adding one solution to the other until the pH of the solution changes from basic to acidic. The point at which this change occurs is called the ‘equivalence point.’ In order to find the equivalence point, it is necessary to take multiple pH readings and plot them on a graph.

The point at which the pH curve changes from sloping upwards to sloping downwards is the equivalence point. Double titrations are a useful tool for finding the exact concentration of an acid or base solution.

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Importance of Double Titration

The double titration method is used when:

– The endpoint of the first reaction is not obvious.

– When the first reaction is too slow.

– When the first reaction mixture is coloured and it is difficult to see the endpoint.

– When back titration is not possible e.g. when the reaction mixture cannot be made basic.

In a double titration, one reactant is titrated against a second reactant. The aim is to find the point at which the two mixtures have reacted in exactly the same way. This is known as the equivalence point.

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Examples of Double Titration

There are lots of examples of double titration in industry and in the laboratory. For example, when making pickles, double titration is used to find the ideal ratio of vinegar to the water. In the laboratory, double titration can be used to find the acidity of a sample or to determine the concentration of an unknown acid.

In a double titration, one solution is added to another until the reaction between the two is just complete. The amount of one solution needed to completely neutralise the other.

Conclusion

Overall, double titration is a very useful technique that can be used to know the volume of an unknown acid or base. By performing a double titration, you can cancel out any errors that may occur due to impurities in the acid or base. This makes double titration a very accurate way to determine the concentration of an unknown acid or base. There are many different types of double titration experiments that can be performed, so it is important to choose the one that is best suited for your needs. With a little practice, you will be able to perform double titration with ease. This article dealt with the meaning of double titration, double titration experiments and examples of double titration.