Various
kinds of 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:
1. Reaction of merging
2. Decomposition reaction
3. Reaction of change (single exchange reaction)
4. Metathesis reaction (multiple exchange reaction)
1.
Reaction Of Merging Or Synthesis 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 chlorine amounts, 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. Decomposition Reactions
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 for the decomposable 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 extracts that can be used as building materials need to be further processed into tohor, 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 Reactions
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 (II) iodide compound. The equation of the reaction:
2KI (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.
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, if 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) → CO¬¬2 (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)
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.
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. 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
Before entering how to
calculate the rendemen we must know the reaction
The ideal chemical yield value (theoretical rendement) is 100%, a value highly
unlikely to be achieved in its practice. Calculate the percentage of rendemen
that is by using the following equations percent rendemen = weight yield /
weight of yield divided by the sample weight multiplied by 100%
What is the function of calculating the rendement of a chemical reaction.
BalasHapusRendement is the ratio of the amount (quantity) of oil produced from the extraction of aromatic plants. Rendemen use percent unit (%). The higher the yield produced, the faster the oil produced.
HapusIncreasing the yield or comparison of the amount of oil that can be done with two approaches,
First, the cultivation process
Second, the process of making oil
The quality of the oil produced is usually inversely proportional to the number of rendaments produced. The higher the resulting rendamen the lower the quality obtained. The formula for calculating the following rendamen:
Rendemen (%) = (jumlah minyak yang dihasilkan)/(jumlah bahan sebelum diolah ) x 100%.
From your post , which one that is your predict ?
BalasHapusIs there any purpose of calculating the yield of the reaction, if any please explain !
BalasHapusTo obtain the efficiency of a reaction is usually also done to prove a theory. Of a reaction rendement
HapusCan you explain abot Metathesis reaction?
BalasHapusMETATESIS REACTION
HapusThe metathesis reaction is an ion-exchange reaction of two salt-forming electrolytes, there are three possible types of saline reactions: LA salt with BX salt, BX salt with HA acid and LA salt with BOH base.
The metathesis reaction is also called the dual displacement reaction involving a solution and exchange of the cations and anions thereof. As for the support in metathesis reaction is the formation of sediment, gas and weak eletrolite. Not only the salt precipitate when the reactant solutions are mixed depending on the concentration of ions that make up the salt. The metathesis reaction is characterized by the exchange of molecular sections between the two reactants.
When the ion concentration is large enough to form the reaction mixture becomes saturated to salt solubility it will form precipitate. Metathesis reaction can occur if one of the reaction products is a precipitate or a gas, in other words one of the reaction products has low solubility in water.
This reaction can generally be written as follows:
AB + CD AD + CB
Metathesis reaction (pair exchange) may occur if AD and CB meet at least one of the following criteria:
1. It is difficult to dissolve in water (settling)
2. Unstable compounds
3. Electrolyte properties are weaker than AB and CD.
please explain to me about prediction from your rendement ?
BalasHapusPlease explain in detail what is the rendemen?
BalasHapusIn 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:
HapusCan you give me example about problem solving to rendement?!
BalasHapus