Using english to predict rendement of product a reaction
RENDEMEN
In chemistry, yield, also referred to as reaction yield, is the amount of
product obtained in a chemical reaction. The absolute yield can be given as the
weight in grams or in moles (molar
yield). The percentage
yield (or fractional
yield or relative
yield), which serves to measure the effectiveness of a synthetic
procedure, is calculated by dividing the amount of the obtained desired product
by the theoretical yield (the
unit of measure for both must be the same):
The theoretical yield
is the amount predicted by a stoichiometry calculation based on the number of
moles of all reactants present. This calculation assumes that only one reaction
occurs and that the limiting reactant reacts completely. However the actual yield
is very often smaller (the percent yield is less than 100%) for several
reasons:
1.
Many reactions are incomplete and the reactants are
not completely converted to products. If a reverse reaction occurs, the final
state contains both reactants and products in a state of chemical equilibrum.
2.
Two or more reactions may occur simultaneously, so
that some reactant is converted to undesired by-products.
3.
Losses occur in the separation and purification of the
desired product from the reaction mixture.
4.
Impurities are present which do not react
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%
Here are some tips you may find handy in helping to predict the type of
reaction that will occur if you know only the reactants. Keep in mind that not
all combiations of chemicals will result in a chemical reaction—these tips are
handy only for helping to predict what would happen should they happen to
react.
- If two ionic compounds are combined, it's usually safe to predict that a double displacement reaction will occur.
- If the chemicals mixed are oxygen and something containing carbon, it's usually a combustion reaction.
- If we start with only one reactant, the reaction taking place is probably a decomposition reaction. To predict the products of such a reaction, see what happens if the chemical breaks into smaller, familiar products such as water, carbon dioxide, or any of the gaseous elements.
- When pure elements are combined, synthesis reactions are the frequent result.
- If a pure element combines with an ionic compound, a single displacement reaction may take place.
- If a compound containing the hydroxide ion is involved, check the other compound to see if it contains hydrogen. If it does, it may be an acid-base reaction.
All chemical reactions can be classified into one
of three categories:
1. Decomposition Reactions
The decomposition reaction is the opposite of the synthesis reaction -
the complex molecule is broken down to make a simpler molecule. These reactions
appear in a general form:
AB -> A + B
One example of a
decomposition reaction is electrolysis of water to make oxygen and hydrogen
gas:
2 H2O -> 2 H2 + O2
2. Burning Reactions
The combustion reaction is when oxygen combines with other compounds to
form water and carbon dioxide. These reactions are exothermic, which means they
produce heat. For example naphthalene combustion reaction. C10H8 + 12 O2 -> 10
CO2 + 4 H2O
3. Acid-base Reactions
This is a special kind of double displacement reaction that occurs when
acids and bases react with each other. H + ions in acid react with OH⁻ ions in the base, causing water formation. Generally, the product of
this reaction is ionic and water salts:
HA + BOH -> H2O + BA
An example of an acid-base reaction
is the reaction of bromide acid (HBr) with sodium hydroxide:HBr + NaOH ->
NaBr + H2O
The efficiency of a chemical reaction can be determined by calculating
the percentage of results. Almost in all reactions, we will get fewer results
than expected. This happens because most of the reactions are equilibrium
reactions, or because of some reaction conditions that cause the reaction not
to run perfectly. Chemists can obtain reaction efficiency by calculating the
following percentage of results:
Percentage of results =
(actual results / theoretical results) x 100%
The real result is how many
products are obtained after the reaction is over. The theoretical result is how
many products are obtained based on stoichiometric calculations. The comparison
of these two results provides an explanation of how efficient the reaction is.
For example, the theoretical result of ferrous metals is 699.47 grams. While
the real result is 525 grams. Therefore, the percentage of the results is:
% Yield = (525 grams /
699.47 grams) x 100% = 75.05%
The 75% yield percentage is
not a too bad result.
What is the difference between real yield and theoretical rendement?
BalasHapusThe 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%
HapusWhat is the purpose of rendemen calculation?
BalasHapusThe 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:
HapusCan you give an example of your explanation of "Impurities are present which do not react"?
BalasHapusThis is an example of an esterification reaction where one molecule acetic acid reacts with one molecule ethanol, yielding one molecule ethyl acetate (a bimolecular second-order reaction of the type A + B → C):
HapusWhat is the meaning of synthesis reaction?
BalasHapusA synthesis reaction or direct combination reaction is one of the most common types of chemical reactions. In a synthesis reaction two or more chemical species combine to form a more complex product.
HapusA + B → AB
In this form, a synthesis reaction is easy to recognize because you have more reactants than products. Two or more reactants combine to make one larger compound.
One way to think of synthesis reactions is that they are the reverse of a decomposition reaction.
You said, For example naphthalene combustion reaction. C10H8 + 12 O2 -> 10 CO2 + 4 H2O. If it is known 15gr CO2, what is the volume of O2 when STP?
BalasHapusC10H8 + 12 O2 -> 10 CO2 + 4 H2O
HapusKnown: mass of Co2 = 15 gram
So = mole Co2= mass : Mr = 15:44 = 0,3 mole
And mole O2 = 12: 10 ×0,3 = 0,36
The end volume O2 = Mole × 22,4 = 0,36 × 22,4= 8,064
Many reactions are incomplete and the reactants are not completely converted to products Why it can be happen?
BalasHapusChemical equilibrium can be disturbed by some external factors. For example, in the previous Haber process discussion, it is known that the Kc value in the Haber process is 3.5.108 at room temperature. This large value indicates that at equilibrium, there is a lot of ammonia gas produced from nitrogen gas and hydrogen gas. However, there is still remaining nitrogen gas and hydrogen gas at equilibrium. By applying the economic principle in the industrial world, it is expected that as much as possible the reactants are converted into products and the reaction is complete. In order to obtain more product in quantity, equilibrium can be manipulated using Le Chatelier principle.
HapusA French chemist Henri Le Chatelier finds that if a balanced chemical reaction receives a change of state (accepting action from the outside), the reaction will lead to a new equilibrium with a certain shift to overcome the accepted change (reacting in response to change be accepted). This is called Le Chatelier Principle.
There are three factors that can change the chemical equilibrium, among others:
Concentrations of reactants or products
Temperature
Pressure or volume on the system containing the gas phase
Give me another example of the Decomposition Reaction. And tonlong explain!
BalasHapusIn the decomposition reaction that occurs is the opposite of the merging reaction. Where a substance decomposes into two or more new substances.
HapusExamples of decomposition reactions eg in the process of electrolysis water into hydrogen gas and oxygen gas using electricity, the reaction is as follows: 2H2O () → 2H2 (g) + O2 (g)
2 NH3 → N2 + 3H2
C2H6 → 2 C + 3 H2
While the decomposition of the compound into a more simple compound, such as:
H2CO3 → H2O + CO2
CaCO3 → CaO + CO2
What is the another examples for innert gass so not at all elements can be reacted with it? @hudiaumamifaisal
BalasHapusInert is a term in English which means in a state of not doing anything at all or doing something very small effect. The term inert is used in many respects, especially chemistry to illustrate that a compound or chemical resistant substance.
HapusThe inert term is used to define a substance that does not react chemically. The precious gas was previously known as an inert gas because of its low level of participation in chemical compounds. The reason why this happens is because their outermost electron shell is completely filled, so they have a low probability of getting or losing electrons. It is now known that this gas actually reacts to form chemical compounds such as xenon tetrafluoride.
Nitrogen gas may react with lithium alkali metal to form lithium nitride compounds (Li3N), even under normal conditions. Under conditions of high pressure and temperature with proper catalyst, nitrogen becomes reactive, as in the Haber process used to produce ammonia as a fertilizer feedstock.
what the meaning of If two ionic compounds are combined, it's usually safe to predict that a double displacement reaction will occur.
BalasHapusIt includes gand swap reactions in which the metathesis reaction or double exchange reaction is a reaction involving the exchange of parts of the reactant. If the reagents are ionic compounds in solution form, the exchange portion is the cation and anion of the compound. For example a colorless potassium iodide solution is mixed with lead (II) nitrate solution which is also colorless. The ions in the solution react to form a yellow precipitate of the lead (II) iodide compound. The equation of the reaction:
Hapus2KI (aq) + Pb (NO3) 2 (aq) → 2KNO3 (aq) + PbI2 (s)
Iodide ions in the potassium iodide solution exchange with nitrate ions from lead (II) nitrate solution, yield a colorless potassium nitrate solution and a yellow i (y) iodide lead solid, as PbI2.
The acid and base reaction that produces salt, is also considered a metathesis reaction. For example the reaction between hydrochloric acid, HCl (aq) and sodium hydroxide (aq), the equation of the reaction:
HCl (aq) + NaOH (aq) → NaCl (aq) + H2O (l)
The acid-base reaction is also called the neutralization reaction, because it occurs the inclusion of the H + charge by the electrically neutral (H2O) water-formed OH. The salt of NaCl formed remains in solution as its ions.
Whether glucose can experience a combustion reaction? Explain
BalasHapusYa, jika dilakukan obat Pembakaran 'adalah suatu runutan reaksi kimia antara suatu bahan bakar dan suatu oksidan, disertai dengan produksi panas yang kadang-kadang disertai cahaya dalam bentuk pendar atau api.
HapusDalam suatu reaksi penuh, suatu zat mengandung zat pengoksidasi, dan produknya adalah zat dari setiap unsur dalam bahan bakar dengan zat pengoksidasi. Contoh:
CH 4 + 2 O 2 → CO 2 + 2 H 2 O + panas {\ displaystyle CH_ {4} + 2O_ {2} \ rightarrow \; CO_ {2} + 2H_ {2} O + {\ textrm {panas}}} {\ Displaystyle CH_ {4} + 2O_ {2} \ rightarrow \; CO_ {2} + 2H_ {2} O + {\ textrm {panas}}}