Is it possible to have 100 recovery of a compound

This means the product has an amount than expected from theoretical calculations. This is possible because there can be some other chemical reactions in the same reaction mixture that produce the same product. However, it can also be due to the presence of impurities. Ex: When CaCO 3 Therefore, one mole of calcium carbonate should give 1 mole of calcium oxide. But in this experiment, Then the amount of CaO should be given is,. Percent recovery is the amount of a product obtained after its synthesis and purification.

The percent recovery can be used to determine the efficiency of the synthesis reaction. This term is often used in organic chemistry to determine the yield obtained from recrystallization. The recrystallization process is used to obtain a purified product. Most of the times the final product given by chemical synthesis has many impurities. Therefore, purification is an essential step in organic synthesis reactions.

In the recrystallization process, the compound to be purified is mixed with a suitable hot solvent and is stirred well. Studying how much of a compound is produced in any given reaction is an important part of cost control. Chemical reactions in the real world don't always go exactly as planned on paper. In the course of an experiment, many things will contribute to the formation of less product than predicted. Besides spills and other experimental errors, there are usually losses due to an incomplete reaction, undesirable side reactions, etc.

Chemists need a measurement that indicates how successful a reaction has been. This measurement is called the percent yield. To compute the percent yield, it is first necessary to determine how much of the product should be formed based on stoichiometry. This is called the theoretical yield , the maximum amount of product that can be formed from the given amounts of reactants. The actual yield is the amount of product that is actually formed when the reaction is carried out in the laboratory.

The percent yield is the ratio of the actual yield to the theoretical yield, expressed as a percentage. Percent yield is very important in the manufacture of products. Much time and money is spent improving the percent yield for chemical production. When complex chemicals are synthesized by many different reactions, one step with a low percent yield can quickly cause a large waste of reactants and unnecessary expense.

When a chemist synthesizes a desired chemical, he or she is always careful to purify the products of the reaction. Potassium chlorate decomposes upon slight heating in the presence of a catalyst, according to the reaction below:. First, we will calculate the theoretical yield based on the stoichiometry. Step 1: Identify the "given" information and what the problem is asking you to "find". Day 2 procedures: Quantitate benzoic acid recovery; determine percent yield Melt temperature determination of purified benzoic acid.

Safety: Acetone is a flammable liquid and a severe eye irritant; Methanol is a flammable liquid, an irritant, is toxic, and has harmful vapors; Petroleum ether ligroin is a flammable liquid, an irritant, and is toxic; Toluene is a flammable liquid, a severe irritant, is toxic, and has harmful vapors; no flames in allowed in lab, and be sure to wear gloves while handling it, and to wash both your gloves and your hands after handling it.

Also, avoid breathing the vapors of any of these compounds. The solid unknowns are all toxic and irritants, and you should avoid contact with them, as well as breathing their vapors. Using available reference sources MSDS or other sources , determine which of the following solvents would "likely" be the best to re-crystallize benzoic acid. Take into account solubility of benzoic acid in the different solvents, and examine their potential to dissolve a little bit at a lower temperature, but more at a higher temperature.

So, for this experiment, weigh out five 0. To each test tube add 5 mL of appropriate solvent. To do this, it would probably be best to use a single mL graduated cylinder for for each solvent.

Therefore, it is time to share as a bench of different groups. One group will label one of their mL graduated cylinders with one of the solvents.

Another group provides the graduated cylinder for another solvent, and so forth. This way, you do not potentially mix one solvent with another. After you add the 5 mL of each solvent to the appropriately labeled test tube containing 0. For example, if one of the solvents easily dissolves the benzoic efficiently, it would like not be the best solvent. Then, place the tubes in a boiling water bath and as the temperature rises use a digital thermometer to monitor temperature periodically swirl the contents of the tube and see which solvent dissolves the benzoic acid the best.

The solvent that dissolves benzoic acid the best is probably not the best solvent for re-crystallization. For example, acetone has a boiling point around 56 o C. So, you may want to only increase the temperature up to about 50 o C for these comparisons. During the first day of this experiment, you relied on some of the physical properties of benzoic acid to purify it using re-crystallization procedures.

It is also possible to purify a chemical based on chemical properties. It is generally understood that organic compounds that are uncharged will most often not be soluble in water. Conversely, charged organic compounds generally are not soluble in organic solvents. Such is the case with benzoic acid. As an acid, benzoic acid is a proton donor, and when it loses its proton, the charged benzoate ion is produced. The solubility of benzoic acid in water at room temperature is small, but the solubility of the benzoate ion is very high in water.

To do this experiment, obtain about 1. Add You should observe that all the benzoic acid dissolves at room temperature. You now have a solution containing sodium benzoate. You have effectively taken a non-soluble solute and made it soluble using one of its chemical properties acids are neutralized by base. Obviously, you will not be able to collect crystals of this solution because the benzoate ion, even at cooler temperatures will not precipitate out.

Since the benzoate ion is fully soluble in aqueous solutions, you cannot for crystals. But what you can do, is now take advantage of the fact that while benzoate ion is soluble, converting this ion back into benzoic acid would produce solid benzoic acid which can be collected via filtration. To do this, you will need to add to your solution enough acid you will be using HCl to make the mixture acidic to a pH of about 1 use appropriate pH paper which allows you to determine the pH.

Start adding some of the 3 M HCl to your beaker. A large amount of solid material should be present. Once you have collected most of your crystals, use some ice-cold DI water to wash the crystals in the funnel.

Transfer the crystals to a labeled evaporating dish, or beaker, and let dry until the next lab period. During the next lab period, you will do a yield, percent yield, and melt temp on your material. Just be aware, that the melting point you observe may not be the best since there might still be some salt in the solid. Before you do your melt temps, you will need to get some physical information about each of the chemicals listed below. Use any reference source including the internet to obtain these data values.

Place the appropriate information in the table below.