Predict Rendement of Product a Reaction

Predict Rendement of Product a Reaction 

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. [1] 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 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 percent of rendemen that is by using the following equations percent rendemen = weight yield / weight of yield divided by the sample weight multiplied by 100%
In determining the direction of a chemical reaction we must rely on an understanding based on a number of factors, and contributions that are not always easy to assess. Although the assessment is prone to error, but it is usually reliable where it seems reasonable to try, and that is certainly to answer ignorance.
In predicting chemical reactions there are several known factors such as, if the free energy of a reaction is known, then there is no problem predicting a chemical reaction. Then if only enthalpy changes are known, then predictions usually apply to room temperature but are more or less reliable as well for higher temperatures. If the reaction occurring in the solution and the oxidation potential of the involved compound is known then the prediction is relatively simple, and this oxidation potential buys a rough guide for possible reactions in the absence of a solvent. If the equilibrium constant is known, relating to ΔG0 = - RH in K gives us a change of free energy. But information like this is still lacking, so we must rely on our understanding of the preceding principles. For chemical reactions at room temperature the expected entropy changes are not so great that the relative strength of the reactants and the products produced will guide the course of the reaction. Here are the rules that may be useful and will be used.
 Reactions tend to occur where the bonds of the orbital and some of the electrons are available and allow for attractive tensile interactions between atoms.

The types of reactions that are predicted by this kind are most only some of them as follows:
(1) Synthesis - a direct combination of elements or compounds,
(2) Substitution - transfer of one element or compound, from excessive complex combinations with other elements or compounds, and
(3) Metathesis - double decomposition, or exchange partner.

In chemistry, the Le Chatelier principle, also called Le Chatelier or "Equilibrium Law", can be used to predict the effect of changes in conditions of chemical equilibrium. This principle is named after Henry Louis Le Chatelier and sometimes from Karl Ferdinand Braun who discovered this principle independently. This principle can be expressed as:
When a system at equilibrium changes its concentration, temperature, volume, or pressure, the system adjusts (partially) itself to eliminate the effect of applied change and a new equilibrium is reached.
In other words, every time the system is in equilibrium disturbed the system will adjust in such a way that the effect of the change will be canceled.
This principle has various names, depending on the disciplines that use them (see homeostasis, a term commonly used in biology). The Le Chatelier Principle also serves as the basis for more general observations in society, [1] which roughly state that:
Any change in the status quo will produce the opposite reaction of the system in question.
In chemistry, this principle is used to manipulate the results of a reversible reaction, often increasing the reaction yield. In pharmacology, the binding of the ligand at the receptor can shift the equilibrium according to Le Chatelier principle, so as to explain the various phenomena of activation and desensitization of the receptor. [2] In economics, this principle has been generalized to help explain the price balance of an efficient economic system.
Example:
1. In 50 grams of urea fertilizer (CO (NH2) 2) there are 21 grams of nitrogen. The purity of urea fertilizer is ...

Answer:
If you find a question that asks for purity then all you have to compare facts with theory.

FACT in Problem:
In 50 grams of urea fertilizer (CO (NH2) 2) there are 21 grams of Nitrogen (N)

THEORY:
 

COMPARE: