using english to predict rendement of product a reaction
RENDEMENT
Understanding
rendement
In chemistry, the yield of the chemical, the yield
of the reaction, or only the rendement refers to the amount of reaction product
produced in the chemical reaction. The absolute rendement may be written as a
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 percentage of rendement that is by using the following equations
percent rendemen = weight yield / weight rendemen divided by 100% of the sample
weight.
Chemical
Reactions
By knowing some properties or types of reactions, we
can understand the chemical reactions more easily. Generally, chemical
reactions are classified by type as follows:
• Combination reaction
• Decomposition reaction
• Change reactions (single exchange reactions)
• Metathesis reaction (multiple exchange reaction)
1.
Reaction
Reaction
The
merging reaction is a reaction in which two substances merge to form a third
substance. The simplest case is when two elements react to form a compound. For
example sodium metal reacts with chlorine gas to form sodium chloride. The
equation of the reaction:
2Na (s) + Cl2
(g) → 2NaCl (s)
Other
examples are the reaction between white phosphor and chlorine gas. In limited
amounts of chlorine, phosphorus reacts to form phosphorus trichloride, pcl3, a
colorless liquid.
P4 (s) + 6Cl2
(g) → 4PCl3 (l)
If
the excess chlorine is available, the phosphorus compound produced is
phosphorus pentachloride, pcl5, a white solid.
P4 (s) +
10Cl2 (g) → 4PCl5 (s)
Other
merging reactions involve the compound as reagents. For example: phosphorus
trichloride reacts with chlorine gas to form phosphorus pentachloride. The
equation of the reaction:
PCl3 (l) +
Cl2 (g) → PCl5 (s)
2.
REACTION
OF PUNISHMENT
The
decomposition reaction is a reaction when a single compound reacts to form two
or more substances. Usually this reaction requires a rise in temperature in
order for the biodegradable compound by increasing the temperature eg kclo3.
This compound when heated will decompose into kcl and oxygen gas. The equation
of the reaction:
KClO3 (s) →
2KCl (s) + 3O2 (g)
Decomposition
of potassium chlorate is commonly used to generate laboratory oxygen gas.
The
decomposition reaction is commonly applied in limestone processing in the area
of West Java cipatat. Limestone, caco3 digging results that can be used as
building materials need to be further processed into tohor stone, cao. The
processing of limestone is done by way of roasting limestone in the stove. The
chemical equations are:
CaCO3
(s) → CaO (s) + CO2 (g)
In this reaction, a
single compound is broken down into two different substances.
3.
Exchange
reaction
Reaction
of a change or also called a single exchange reaction is the reaction in which
an element reacts with a compound to replace the element contained in the
compound. For example, if the copper metal plate is immersed in a silver
nitrate solution, a silver metal crystalline is produced. The equation of the
reaction is:
Cu(S)
+ 2AgNO3 (AQ) → 2Ag (S) + CU (NO3)2
(AQ)
Copper
replaces the silver contained in silver nitrate, producing a solution of copper
nitrate and silver metal.
If
the logamseng plate is immersed in a blue copper sulphate solution, then on the
surface of the zinc metal there will be a red copper deposit, and the blue
color of the solution slowly fades. This shows that zinc reacts with copper
sulfate to produce copper metal and a colorless zinc sulfate solution.
4.
Metathesis
reaction
The
reaction of metathesis or multiple exchange reactions is a reaction involving
the exchange of parts of the reactants. 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 compound (ii) iodide. The equation of the
reaction:
2Ki (aq) + Pb (NO3)
2 (aq) → 2KNO3 (aq) + Pbi2 (s)
Iodide
ions in a potassium iodide solution exchange with nitrate ions from lead
solution (ii) nitrate, yielding a colorless potassium nitrate solution and a
lead solid (ii) a yellow iodide, 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 charge of h + by electronically neutral (h2o) water
(h2o). The nacl salt formed remains in solution as its ions.
Burning
reaction
The reactions we
consider so far can be characterized as reactor reactions of atoms. However, we
need to add another kind of reaction that is the combustion reaction, which is
characterized by the fact that one of its reactants is oxygen. The combustion
reaction is the reaction of a substance with oxygen, usually reacting rapidly
with the release of heat forming a flame.
If carbon compounds are
burned in oxygen or air will form carbon dioxide and water vapor when the
combustion is complete. However, when incomplete combustion (lack of oxygen)
will form carbon monoxide gas, or may be formed carbon black (soot). Some
examples of combustion of carbon compounds:
CH4 (G) + 2O2
(G) → CO2 (G) + 2H2O (G)
2CH3OH (L)
+ 3O2 (G) → 2CO2 (G) + 4H2O (G)
C4H10
(G) + 13O2 (G) → 8CO2 (G) + 10H2O (G)
Ironing, although not
commonly considered as combustion, is essentially a combustion reaction,
because there is a reaction between iron and oxygen accompanied by the release
of energy. The iron-cellification reactions are in fact very complex involving
water molecules, but we can write the karate in the form of a net reaction,
which is as follows:
4FE (s) + 3O2
(G) + NH2O (L) → 2FE2O3.NH2O
(S)
Determine
the reaction yield using a limiting reagent.
Definition
of Limiting Reagent
The Limiting Reagent is
a completely discharged reactant that determines when the reaction stops. From
the stoichiometric side, you will be able to calculate the exact amount of
required reactants using the exact mole ratio according to the coefficients in
the equivalent reaction. If you do not mix the reactants in the correct
proportions according to stoichiometry, then one of the reactants will be
exhausted while the other will remain. Thus the limiting reagent is a reactant
completely discharged in the reaction and limits the reaction.
How
to Find the Limiting Reagent
There are two ways to find barrier reagents. The
first way is to find the ratio ratio of the number of reactants used in the
reaction (mol ratio). The second way is by calculating the number of grams of
the reaction.
First
step
Respond to the reaction (note the coefficients in
the equivalent reaction)
Convert all reactants into moles (usually just
divide by atomic mass or relative molecules)
Compare the mole in the number 2 by the ratio of the
reaction coefficient to the number 1. You will be able to determine which of
the reactants is exhausted first.
The
second way
Respond to the reaction (note the coefficients in
the equivalent reaction)
Determine the number of moles of each reactant
Adjust to the mole of the reaction using a
coefficient ratio then multiply by its relative molecular mass
That produces the least reaction gram that is the
reagent reagent.
Let us more understand we see the example of the
problem below.
Sample
of Limiting Reagent
In a closed container, 20 grams of methane (CH4)
burned with 64 grams of oxygen (O2) produces carbon dioxide and water vapor
according to the reaction below. Known Mr. methane = 16, Ar oxygen = 16, and
Mr. H2O = 18.
CH4
(g) + O2 → CO2 + 2H2O
Determine the limiting reagents
Resolve the Reaction (already equivalent → given in
the matter)
CH4
(g) + 2O2 → CO2 + 2H2O
Calculate the moles of each reactant
Mol
CH4 = 20/16 = 1.25 mol
Mol
O2 = 64/32 = 2 mol
Adjust the reaction mole and calculate the result of
the reaction
1.25
mol CH4 → 2.5 mol H2O (comparison coefficient 1: 2)
2.5
x 18 = 45 grams of H2O
2
mol O2 → 2 moles H2O (2: 2 mole ratio = 1: 1)
2
x 18 = 36 grams of H2O
So which is a limiting reagent is oxygen (O2)
Example
Known reaction as follows S (s) + 3F2 (g)
-> SF6 (g).
If reacted with 2 mol of S with 10 moles of F2,
determine:
a. How many SF6 mols are formed?
b. Which substance and how many moles of substance
is left?
Answer:
S
+ 3F2 -> SF6
From the reaction coefficient shows that 1 mol of S
requires 3 moles of F2. The possibilities are as follows.
a. If all S reacts then F2 is required:
This is possible because F2 is available
10 mol.
b. If all F2 is reacted then S is
required:
This is unlikely, because the available S is only 2
mol.
So, acting as a limiting reagent is S!
The number of SF6 mols formed = x mol S.
a. Mol SF6 = 1 x 2 mol = 2 mol
b. The remaining substance is F2, as much
as = 10 mol - 6 mol = 4 mol F2
Does this prediction match the result if tested directly?
BalasHapusThis prediction is in accordance with the tested result, because in the above reaction the reaction is actually what happens when two or more compounds are reacted.
HapusWhat is the usefulness of rendement in chemical calculation ?
BalasHapusTo know the amount of product of the reaction in the form of gram or mol.
HapusWhat causes the rendemen can not reach 100%?
BalasHapusThis is because the ideal chemical yield value (theoretical rendement) is 100%, a value which is highly unattainable 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%.
HapusDescribe the relation of the limiting reagent with stoichiometry.
BalasHapusIn a chemical reaction, the mole ratio of the added reagents is not always the same as the ratio of the reaction coefficient. This causes a reagent to be reacted first. Such reagents are called limiting reagents.
Hapuswhy Reaction of a change or also called a single exchange reaction?
BalasHapusSubstitution Reaction is the reaction of replacement (exchange) of an atomic group by another atom group. In substitution reactions there is no change of bond, single bond -> single bond.
HapusExample:
-Reaction of propane monochlorination (replacement of one H atom by one Cl atom), for example: C3H8 + Cl2 -> C3H7Cl + HCl
-Reaction of propane dibrominasi (replacement of two H atoms by two Br atoms), for example: C3H8 + 2Br2 -> C3H6Br2 + 2HBr
In this exchange reaction that occurs is the exchange of an atomic group by another tom group.
In the burning reaction, what causes the color difference of the fire, and what is its effect?
BalasHapusThe color of fire is strongly influenced by the electrons in a constantly moving fire. Each element has a certain emission spectrum and when it is highlighted by fire, it will emit electromagnetic radiation that will produce a beam of fire with certain colors.
HapusIn theory, fire occurs from the combustion reaction of oxygen-containing compounds (O2). If a combustion reaction lacks oxygen, then the combustion efficiency decreases and produces a carbon compound such as smoke (soot). For example, the candle will die because if it is closed with a glass. Because he lacks oxygen. Factors that affect the color of flame are physical factors (temperature) and chemical factors (substances that megalami reaction).
In the burning of sodium will produce orange apri, combustion of strontium chloride yield red color, burning potassium nitrate to produce purple color, burning boron produce green color, burning of copper yield blue color, and so on.
The red fire is generally temperatures below 1000 degrees Celsius. Blue-colored fire, higher than red fire, but still below 2000 degrees Celsius. Then a hotter fire, a white fire that temperatures above 2000 degrees Celsius. This fire is also contained in the core of the sun. White fire is also used in industries that produce iron and the like. The hotest fire is a black fire (reportedly this type of fire is only found in hell)
Please explain and give examples of Reaction decomposition?
BalasHapusBinary compounds are compounds consisting of only two elements. The simplest type of decomposition reaction is when the binary compound decomposes into its elements. Mercury (II) oxide, red solids, decomposes when heated to produce mercury and oxygen gas.
Hapus2HgO(s) → 2Hg(l) + O2 (g)
What exactly happen so that thethe result of the teory is always getter than result of practices, can you give me an example?
BalasHapusIn the practicum usually the practitioners are less good at experimenting. So the experiment becomes error, not the result of the lab does not match the theory that has been put forward by the experts.
Hapusgive me an example of rendement in our daily life?
BalasHapusCombustion reactions
HapusEvery time we light a match, burn a candle, make a fire, or light a grill, we will see a burning reaction. Combustion combines energetic molecules with oxygen to produce carbon dioxide and water.
For example, propane combustion reactions, found in gas grills and some fireplaces, are:
C3H8 + 5O2 → 4H2O + 3CO2 + energy
Write down the equation of the reaction in the reaction of the law
BalasHapusAl + H2SO4 → Al2(SO4)3 + H2
Hapusstep 1 : The most complex chemical formula of Al2 (SO4) 3
step 2 : a Al + b H2SO4 → 1 Al2(SO4)3 + c H2
step 3 : 2Al + 3H2SO4 → Al2(SO4)3 + 6H2