Rendement

Rendement is actually a term in the field of chemistry studies. Rendement image of the reaction results inaccuracy, where the result is always lower than the mathematical calculation. For example, in a chemical reaction, it should produce a weight of 100 grams, mathematically, but at a yield of only 90 grams. Unconsciously this also often happens in our daily lives.

            In chemistry, the chemical yield, the yield of the reaction, or only the rendement refers to the amount of reaction product produced in the chemical reaction. Absolute rendement can be written as weight in grams or in moles (molar yield). The relative yield used as a calculation of the effectiveness of the procedure is calculated by dividing the amount of product obtained in moles by the theoretical yield in moles

To obtain a percentage yield, multiply the fractional yield by 100%.

One or more reactants in chemical reactions are often used redundantly. The theoretical rendement is calculated based on the number of moles of the limiting reagent. For this calculation, it is usually assumed that there is only one reaction involved.

The ideal chemical yield value (theoretical rendement) is 100%, a value highly unlikely to be achieved in its practice. Calculate the percentage of rendement that is by using the following equations percent rendemen = weight yield / weight of yield divided by the sample weight multiplied by 100%

Example :

1.     1.  If 204 grams of bauxite (Mr. Al2O3 = 102) is perfectly reduced yields 54 grams of aluminum metal (Ar Al = 27). The percentage of Al2O3 in the trailer is ...

Answer:

In this case we are asked to calculate the percentage of Al2O3 in the trailer.

This means the trailer is not pure containing 100% bauxite.

So, our task in solving this problem is to seek the purity of the bauxite footage.

Just like the example of question 1, to do this we must also compare FACT with THEORY

FACT: Al periods produced from 204 grams of Al2O3 compounds

THEORY: 

Do any of you ask, why use the facts about the time of Al when the question is% Al2O3?

Let us try by comparing the Facts and Theories of Al2O3's time

FACT: Al2O3 (bauxite) season is 204 grams,

THEORY: Al2O3 period in theory we can calculate from the Al period obtained from the footage

      So we can conclude that we can calculate the purity of a compound just looking from the elements contained in the compound's facts and theories.

Purity (percentage) = Compare FACTS with THEORY

 2.   2.   If the reaction between 6 grams of ethane C2H6 (Mr = 30) with 7.1 grams of Cl2 (Mr = 71) yields 5.16 grams of C2H6Cl (Mr = 64.5) then the percentage of ethylchloride rendement is ...

Answer:

In this case we are required to calculate% C2H6Cl, so let's compare facts and theories:

FACT:

The resulting C2H6Cl period = 5.16 grams

THEORY:

We look for the C2H6Cl period that results from the reaction

The reaction is happening

Theoretically C2H5Cl resulting from the reaction is 0.2 mol