Answer:
B. Oxygen
Explanation:
Basically count each arrow since each arrow represents an electron. Then use the periodic table to find the element with 8 electrons, which is oxygen. Also, if you know the orbital patterns, you can identify that the 2p orbital represents an element in Group 16.
What is conservation area write in 8 points
Answer:
The Conservation area is the pay way to the special architectural and historic interest these are special character.
Explanation:
Conservation area is the features of building and use that historical development to contribute to its special character material and style.
Conservation area is that contain process to the application management development process and local residents.Conservation is that the produce demolition of a building structure with the conservation area,contribute to the group in individually.Conservation area that are special protection in the trees to the dangerous tree and some of the fruit trees.Conservation area are often to the protected by their building, planning works, these character area of appearance.Development rights to the conservation area require to the planning and permission to the outside area.Conservation area is classified to the regulation and the restricted area to the department planning.Conservation area is a composed to the impact of materials and building and the setting of impact.The new development in the conservation area is to the process of the renewal and the managed in the conservation area.4. (01.05 MC)
Rubbing alcohol evaporates from your arm quickly, leaving a cooling effect on your skin. How do the molecules of gas compare to the molecules as a liquid? (4 points)
The gas particles move faster, have the same molecular composition, and have weaker attractions between them than the liquid particles
The gas particles move faster than the liquid particles, and the bonds of the molecules are broken during evaporation to allow gas atoms to spread apart.
The gas particles move slower but have the same molecular structure and the same attraction between them as the liquid particles.
The gas and liquid particles move at the same speed, but the bonds of the molecules are broken during evaporation to allow the gas atoms to spread apart
Answer:
The correct option is;
The gas particles move faster, have the same molecular composition, and have weaker attractions between them than the liquid particles
Explanation:
The properties of the gas molecules in comparison to liquids are
1) The gas molecules are widely spread out
2) After evaporation and while in conditions favorable to the gaseous state, the kinetic energy of a gas is larger than the inter molecular attractive forces
3) A gas fills the container in which it is placed
For liquids
1) There are strong intermolecular forces holding the molecules together in a liquid
2) Liquid attractive forces in a liquid are strong enough to hold neighboring molecules
3) The volume of a liquid is definite.
2.A helium-filled balloon has a
volume of 48.0 L at 25°C and
1.05 atm. What volume will it
have at 0.860 atm and 15°C?
Answer:
The volume at 0.860 atm and 15°C will be 56.638 L
Explanation:
Gay Lussac's law explains the variation in the pressure of a gas by modifying its temperature, keeping the volume constant: it determines that pressure and temperature are directly proportional quantities. In other words, Gay-Lussac's law states that when a gas undergoes a constant volume transformation, the ratio of the pressure exerted by the temperature of the gas remains constant:
[tex]\frac{P}{T}=k[/tex]
On the other hand, Boyle's law determines that the pressure exerted by a gas is inversely proportional to its volume at constant temperature. This is expressed mathematically as:
P*V=k
Finally, Charles's law says that at constant pressure, the volume of an ideal gas is directly proportional to its absolute temperature and is expressed mathematically as:
[tex]\frac{V}{T}=k[/tex]
Combined law equation is the combination of three gas laws called Boyle's, Charles's and Gay-Lussac's law:
[tex]\frac{P*V}{T}=k[/tex]
When you want to study two different states, an initial one and a final one of a gas, you use:
[tex]\frac{P1*V1}{T1}=\frac{P2*V2}{T2}[/tex]
In this case:
P1= 1.05 atmV1= 48 LT1= 25 C= 298 K (being 0 C= 273 K)P2= 0.86 atmV2= ?T2= 15 C= 288 KReplacing:
[tex]\frac{1.05 atm*48 L}{298 K}=\frac{0.86atm*V2}{288 K}[/tex]
and solving:
[tex]V2=\frac{288 K}{0.86 atm} *\frac{1.05 atm*48 L}{298 K}[/tex]
you get:
V2= 56.638 L
The volume at 0.860 atm and 15°C will be 56.638 L
How many protons does an atom of zinc contain?
It contains an amount
a single neutral atom of zinc has 30 protons
I'll GIVE BRAINLIEST: In a redox reaction, CO is changed to CO2. How many electrons must be lost or gained by C and why?
Answer:
C is gaining 2 electrons
Explanation:
O has a 2- charge so for CO to pick up another O atom would add 2 more electrons.
Answer:
C gains 2 electrons
Explanation:
In the redox reaction, CO is changed into CO2 which means there is an additional oxygen. Oxygen loses 2 of its electrons in order to neutralize. So, C must be gaining 2 electrons in order to make the bond.
Ranjana has two unknown solutions X and Y
WILL GIVE BRAINLIEST, Which of the following would have the greatest amount of surface area?
A. 1 cubic foot of watermelons
B. 1 cubic foot of matchbox cars
C. 1 cubic foot of loose sand
D. A 1 cubic foot block of concrete
Answer:
C. 1 cubic foot of loose sand
Explanation:
For many objects having equal volume , surface area will be maximum
of the object which has spherical shape .
But when a sphere is broken into tiny small spheres , total surface area of all the small spheres will be more than surface area of big sphere .
Hence among the given option , surface area of loose sand will have greatest surface area . Loose sand is equivalent to small spheres .
Answer:
the answer would be C 1 cubic foot of loose sand.
What mass of Fe(OH)3 is produced when 35 mL of 0.250 M Fe(NO3)3 solution is mixed with 55 mL of a 0.180 M
KOH solution? (this is a limiting reactant problem).
Answer:
0.35 g.
Explanation:
We'll begin by calculating the number of mole of Fe(NO3)3 in 35 mL of 0.250 M Fe(NO3)3 solution.
This is illustrated below:
Molarity of Fe(NO3)3 = 0.250 M
Volume = 35 mL = 35/1000 = 0.035 L
Mole of Fe(NO3)3 =?
Molarity = mole /Volume
0.250 = mole of Fe(NO3)3 / 0.035
Cross multiply
Mole of Fe(NO3)3 = 0.25 x 0.035
Mole of Fe(NO3)3 = 8.75×10¯³ mole
Next, we shall determine the number of mole of KOH in 55 mL of 0.180 M
KOH solution. This is illustrated below:
Molarity of KOH = 0.180 M
Volume = 55 mL = 55/1000 = 0.055 L
Mole of KOH =.?
Molarity = mole /Volume
0.180 = mole of KOH /0.055
Cross multiply
Mole of KOH = 0.180 x 0.055
Mole of KOH = 9.9×10¯³ mole.
Next, we shall write the balanced equation for the reaction. This is given below:
3KOH + Fe(NO3)3 —> Fe(OH)3 + 3KNO3
From the balanced equation above,
3 moles of KOH reacted with 1 mole of Fe(NO3)3 to produce 1 mole of Fe(OH)3.
Next, we shall determine the limiting reactant. This can be obtained as follow:
From the balanced equation above,
3 moles of KOH reacted with 1 mole of Fe(NO3)3.
Therefore, 9.9×10¯³ mole of KOH will react with = (9.9×10¯³ x 1)/3 = 3.3×10¯³ mole of Fe(NO3)3.
From the above illustration, we can see that only 3.3×10¯³ mole out of 8.75×10¯³ mole of Fe(NO3)3 given is needed to react completely with 9.9×10¯³ mole of KOH.
Therefore, KOH is the limiting reactant and Fe(NO3)3 is the excess reactant.
Next, we shall determine the number of mole of Fe(OH)3 produced from the reaction.
In this case, we shall use the limiting reactant because it will give the maximum yield of Fe(OH)3 as all of it is consumed in the reaction.
The limiting reactant is KOH and the mole of Fe(OH)3 produce can be obtained as follow:
From the balanced equation above,
3 moles of KOH reacted to produce 1 mole of Fe(OH)3.
Therefore, 9.9×10¯³ mole of KOH will react to produce = (9.9×10¯³ x 1)/3 = 3.3×10¯³ mole of Fe(OH)3.
Finally, we shall convert 3.3×10¯³ mole of Fe(OH)3 to grams. This can be obtained as follow:
Molar mass of Fe(OH)3 = 56 + 3(16 + 1) = 56 + 3(17) = 107 g/mol
Mole of Fe(OH)3 = 3.3×10¯³ mole
Mass of Fe(OH)3 =?
Mole = mass /Molar mass
3.3×10¯³ = Mass of Fe(OH)3 / 107
Cross multiply
Mass of Fe(OH)3 = 3.3×10¯³ x 107
Mass of Fe(OH)3 = 0.3531 ≈ 0.35 g.
Therefore, 0.35 g of Fe(OH)3 was produced from the reaction.
what is a disavanege for renewable solor power
Which statement best describes a compound formed by an ionic bond?
A) negatively charged
B) neutral
C) contains multiple charges
D) positively charged
Answer is D
Explanation:
Answer:
B. Neutral
Explanation:
When there is a ionic bond, one element steals or takes away an electron from the other element.
An example is NaCl
In this compound, Chlorine atom steals an extra electron from Sodium to fill its outer shell. So, this is a Ionic bond. Since, the Sodium compound gives away an atom, it is positively charged. Since, Chlorine steals an atom, it is negatively charged. Opposite charges attract, so they become a compound.
When positive and negative mix, it becomes neutral.
pls balance the following chemical equation asap; Ca(OH)2 +CO2 = CaCO3+ H2O pls make it step by step
Answer:
Explanation:
Start by writing water as HOH
Ca(OH)2 +CO2 = CaCO3+ HOH
Next pay attention to the CO2 going to CO3
We need an oxygen.
Fortunately that is provided by the (OH)2
Now we have
Ca(OH)2 + CO2 ==> CaCO3 + HOH
and believe it or not, that is balanced as it is
The left side has 1 Ca. So does the right side
The Left side has 1 C. So does the right side.
The left side has 2 H. So does the right side
The left side has 2 oxygens (in Ca(OH2)) + 2 oxygens in CO2
So the equation is balanced.
One to two paragraphs describing the water cycle
Answer:
The water cycle or hydrologic is a continuous cycle where water evaporates, travels into the air and becomes part of a cloud, falls down to earth as precipitation, and then evaporates again. This repeats again and again in a never-ending cycle. Water keeps moving and changing from a solid to a liquid to a gas, over and over again.
Precipitation creates runoff that travels over the ground surface and helps to fill lakes and rivers. It also percolates or moves downward through openings in the soil to replenish aquifers under the ground. Some places receive more precipitation than others do. These areas are usually close to oceans or large bodies of water that allow more water to evaporate and form clouds. Other areas receive less precipitation. Often these areas are far from water or near mountains. As clouds move up and over mountains, the water vapor condenses to form precipitation and freezes. Snow falls on the peaks.
The continual movement of water on, above, and below the Earth's surface is referred to as the water cycle, also known as the hydrological cycle.
What is water cycle ?The water cycle demonstrates how water is constantly moving both inside the Earth and in the atmosphere. It is a complicated system with a wide range of processes.
Water vapor is created when liquid water evaporates, and this water vapor then condenses to form clouds and falls back to earth as rain and snow.
The constant flow of water between the ground and the atmosphere is known as the water cycle. Water travels to land as precipitation, like snow and rain.
The cycle is then completed by the water evaporating, condensing into clouds in the atmosphere, and precipitating once more on earth. The water cycle is composed mostly of four processes: evaporation, convection, precipitation, and collection.
Thus, The continual movement of water on, above, and below the Earth's surface is referred to as the water cycle.
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11. Samantha was asked to measure out 10 g of salt in a lab. She mistakenly measures out 15 g instead. Calculate
the percent error. Make sure your answer has the correct number of significant figures!
Answer:
50%
Explanation:
Expected measurement required = 10g
Actual measurement observed = 15g
The percentage error is given as proportion the difference between the actual and expected measurement or values and the expected value value expressed as a percentage.
[(Actual - Expected) / Expected] × 100%
[(15 - 10) / 10)] × 100%
(5 / 10) × 100%
0.5 × 100%
50%
Therefore, the percentage error in the measurement is 50%
A chemical engineer is developing a process for producing a new chemical. One step in the process involves allowing a solution of potassium hydroxide to react with a solid. Which action would most likely increase the reaction rate for this step? using larger pieces of the solid using a more concentrated potassium hydroxide solution adding water to the system
Answer:
using a more concentrated potassium hydroxide
Explanation:
The option that would likely increase the rate of reaction would be to use a more concentrated potassium hydroxide.
The concentration of reactants is one of the factors that affect the rate of reaction. The more the concentration of the reactants, the faster the rate of reaction.
Granted that there are enough of the other reactants, increasing the concentration of one of the reactants will lead to an increased rate of reaction.
Hence, using a more concentrated potassium hydroxide which happens to be one of the reactants would likely increase the rate of reaction.
Answer:
using a more concentrated potassium hydroxide
Explanation:
An atom of nitrogen has seven electrons. Which diagram correctly represents the arrangement of these electrons?
ОА.
OB
1112
1s 11:28 1111
2p
1s 12
2p
1s 12
12s 2p
OD. 1111s 112s
112p
Ос.
Answer:
Option C.
Explanation:
The arrangement of electrons in their orbital follows certain rules.
The Hund's rule practically explained how electrons are distributed in their orbitals.
The Hund's rule states that electrons distributed among the orbitals of the same shell singly (without partner) before pairing occurs.
In the filling of these electrons in their orbitals, we fill in the electron without pairing first because electrons tends to repel each other before filling with the opposite spin as shown in the attached photo.
The number of ATPs per NADH generated by the electron transport system is higher than the number generated per FADH2 because __________. The number of ATPs per NADH generated by the electron transport system is higher than the number generated per FADH2 because __________. NADH is converted to NAD , which increases the charge gradient for ATP synthesis FADH2 has a higher (more negative) redox potential than NADH does electrons from FADH2 are not oxidized all the way to water FADH2 has a lower (less negative) redox potential than NADH does
Answer:
FADH2 has a lower (less negative) redox potential than NADH does
Explanation:
Flavin Adenine Dinucleotide (FAD) and Nicotinamide Adenine Dinucleotide (NAD) are redox cofactors that play important functions for mitochondrial activity and cellular redox balance. Both coenzymes exist in two forms: an oxidized and a reduced, which are abbreviated as NAD/FAD and NADH/FADH2, respectively. These reduced forms (NADH and FADH2) are produced in the Krebs cycle during respiration. FADH2 has lower redox potential than NADH because FADH2 is only capable of activating 2 proton pumps, while NADH can activate 3 proton pumps during the electron transport chain, thereby FADH2 generates a minor number of ATP molecules than NADH.
fill in the blanks with the words given below-
[Atoms, homogeneous, metals, true, saturated, homogeneous, colloidal, compounds, lustrous]
1.An element which are sonorous are called................
2.An element is made up of only one kind of ....................
3.Alloys are ............................. mixtures.
4.Elements chemically combines in fixed proportion to form ........................
5. Metals are................................... and can be polished.
6. a solution in which no more solute can be dissolved is called a .................... solution.
7. Milk is a .............. solution but vinegar is a .................. solution.
8. A solution is a ................... mixture.
pls help, could not get these answers
Answer:
1. Metal.
2. Atom.
3. Homogeneous
4. Compounds.
5. Lustrous
6. Saturated.
7. Colloidal; true.
8. Homogeneous.
Explanation:
1. An element which are sonorous are called metal.
2. An element is made up of only one kind of atom.
3. Alloys are homogeneous mixtures.
4. Elements chemically combines in fixed proportion to form compounds.
5. Metals are lustrous and can be polished.
6. A solution in which no more solute can be dissolved is called a saturated solution.
7. Milk is a colloidal solution but vinegar is a true solution.
8. A solution is a homogeneous mixture.
formula for soda glass
Answer:
composition of soda-lime glass is 73% SiO2 – 15% Na2O − 7% CaO − 4% MgO − 1% Al2O3 [129,132,133].
The Soda glass formula is SiO2, Na2O, CaO, Al2O3, K2O, SO3, MgO, Fe2O3, TiO2
Soda glass is a chemical compound that stands out for being the most widely used material to make windows, bottles, glasses, among others.
This compound is characterized by being chemically stable, reasonably hard, and extremely versatile because it can be recycled since it can be melted to make new products.
Its chemical formula is made up of other compounds such as:
SiO2, is Silicon OxideNa2O, is sodium oxideCaO, is calcium oxideAl2O3, is aluminum oxideK2O, is potassium oxideSO3, is sulfur oxideMgO, is magnesium oxideFe2O3, is iron oxideTiO2, is Titanium OxideAdditionally, the compounds found in the highest proportion in glass are SiO2 (74 atoms) and Na2O (13 atoms).
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Question 9 of 10
How could an electron configuration be used to predict relative atomic size?
A. The more valence electrons listed, the larger the atomic radius.
B. The larger the highest energy level number, the larger the atomic
radius.
C. The more sublevels occupied, the larger the atomic radius.
D. The greater number of total electrons, the larger the atomic radius.
SUBMIT
Answer: B
Explanation: Apex
An electron configuration be used to predict relative atomic size because the larger the highest energy level number, the larger the atomic
radius.
The electron configuration of an element shows the arrangement of electrons in atoms of that element.
As more sublevels are added, repulsion between electrons occupying shells increases causing a greater shielding and consequent increase in the size of the atom.
Hence, the larger the highest energy level number, the larger the atomic
radius.
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What is the formula of the ion hydrogen sulfite, which has a charge of -1
There are two types of ions in chemistry, one is cation and the other is anion. Anion is the negative charge ion. Therefore, the formula of hydrogen sulfite ion is HSO₃⁻
What is chemical Compound?Chemical Compound is a combination of ions, ions forms by combination of element and element forms by combination of atoms in fixed proportion.
According to our question the chemical compound from which hydrogen sulfite ion is coming is sulfurous acid that is H₂SO₃. So to get hydrogen sulfite ion we need to remove one hydrogen ion that is H⁺ from the chemical compound sulfurous acid.
The balanced reaction is
H₂SO₃[tex]\rightarrow[/tex]H⁺ + HSO₃⁻
From above reaction we can see that the charge over hydrogen sulfite ion is -1
Therefore the formula of hydrogen sulfite is HSO3-
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An element’s most stable ion forms an ionic compound with bromine, having the formula XBr2. If the ion of element "X" has a mass number of 230 and has 86 electrons, what is the identity of the element, and how many neutrons does it have?
Answer:
88
Explanation:
The ion has a charge of 2+, therefore the number of neutrons it possess is 86+2
which equals 88
The element X having a mass number of 230 and has 86 electrons is radium and has 142 neutrons.
An atom is composed basically of electrons, protons and neutrons. In a neutral atom, the number of protons and electrons are equal. The number of neutrons is the difference between the mass number and the number of protons (atomic number).
Since we know that the ion of the element X has 86 electrons and the compound formed is XBr2, it then means that neutral X has 88 electrons.
The number of electrons in the neutral atom is the same as the number of protons or atomic number. An element can be identified by its atomic number. The element having atomic number 88 is radium.
The number of neutrons is obtained as;
Mass number - atomic number
230 - 88 = 142 neutrons
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Lab Safety Rule #3 says to always add acids or bases to the solvent and NEVER the other way around true or false?
Answer:
true
Explanation:
The standard laboratory rule is to always add acids or bases to solvent and not the other way round.
The dissolution of concentrated acids/bases in solvents (water) generates heat energy. Thus, if the solvent is added to them, a layer of hot weak acid or base will be formed and this will boil and spray around, causing an explosion.
On the other hand, if acid/base is added to solvents, they flow into the solvents and get diluted immediately without any boiling taking place. Hence, it is safe to add acid/base to solvents and not the other way round.
List down the observations made by Rutherford during the gold foil experiment.
Answer:
1) The volume occupied by an atom is composed of mainly empty space
2) Atoms have a very small, relatively dense, central nucleus that is positively charged
3) The region around the nucleus of an atom are orbited by negatively charged electrons in a the same fashion planets orbit around the Sun.
Explanation:
The selection of gold for the gold foil experiment was due to its ability to be rolled into extremely thin sheets such that it was expected for alpha particle to perforate or pass through the foil.
Determine whether the statement is true or false, and why. "If a theory becomes supported by evidence, it can become a law."
A. False, it should read, "A theory and a hypothesis are already equally supported by evidence, but they have different functions."
B. False, it should read, "If a theory becomes supported by evidence, it can become a hypothesis."
C. True
D. False, it should read, "A theory and a law are already both supported by evidence and are equal, but they have different functions."
Answer: D. False, it should read, "A theory and a law are already both supported by evidence and are equal, but they have different functions."
Explanation:
A "Theory" and a'' Law" in scientific method are already both supported by evidence but they have different function,
The function of " Theory" in scientific method is to give an explanation to the observations and findings gathered during the process. It can be modified, improved or even rejected as more information is being gathered.
While a '' Law '' tends to describe an observed event in nature that is true whenever it is put to test. It does not explain why the occurence or event is true.
How many moles of lithium are in 83 grams of lithium? pls answer :(
Explanation:
89cjowdncu8wncuhrwionu9wjvionajofhjowednuiw4fmji2rn most jom4opr
0.10 moles of sodium sulfate is dissolved into 12 mL of solution. What is the molar concentration of the solution?
Your answer should have two significant figures (round your answer to one decimal place).
the molar concentration should be atleast 5mL off the solution since its disolved
Answer:
8.3
Explanation:
Convert mL to L.
12 mL×1 L1000 mL=0.012 L
Solve for molarity.
Molarity=moles of solute
liters of solution=0.10 mol0.012 L=8.3 M
Mike wants to galvanize iron to protect it from rusting. Which metal should he use?
A
platinum
B.
aluminum
C.
copper
D.
zinc
E.
tungsten
Answer:
D. Zinc.
Explanation:
Galvanization is a metal-coating process which involves the application of a thin layer of zinc to an iron or steel, so as to prevent rusting or corrosion.
The zinc metal protects the iron from rusting by sealing the surface of the iron and thus, preventing weathering and oxidation.
Hence, if Mike wants to galvanize iron to protect it from rusting. The metal he should use is zinc (Zn) because a coating of zinc would protect the iron (Fe) by corroding first when exposed to moisture or the atmosphere.
Answer:
b
Explanation:
What does the second law of thermodynamics say about entropy?
A. Only changes in entropy can be measured.
B. Entropy cannot be created or destroyed.
C. The entropy in a system and its surroundings tends to increase.
D. The entropy in a system is zero at equilibrium.
Answer:
The second law of thermodynamics states that the total entropy of an isolated system can never decrease over time, and is constant if and only if all processes are reversible.
Explanation:
Isolated systems spontaneously evolve towards thermodynamic equilibrium, the state with maximum entropy. hope this helps you :)
The second law of thermodynamics say about entropy The entropy in a system and its surroundings tends to increase.
What is second law of Thermodynamics?According to the second law of thermodynamics, Entropy of the universe keeps on increasing overtime. When the entropy decreases and enthalpy increases the free energy change, ΔG, is positive and not spontaneous, and it does not matter what the temperature of the system is. Temperature comes into play when the entropy and enthalpy both increase or both decrease. The reaction is not spontaneous when both entropy and enthalpy are positive and at low temperatures, and the reaction is spontaneous when both entropy and enthalpy are positive and at high temperatures. The reactions are spontaneous when the entropy and enthalpy are negative at low temperatures, and the reaction is not spontaneous when the entropy and enthalpy are negative at high temperatures.
Therefore, The second law of thermodynamics say about entropy The entropy in a system and its surroundings tends to increase.
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The number of atoms in 2.0 moles of NaOH is _____ of 1.0 mole of H2O.
twice that
less than
more than
the same as
Answer:
The answer is the same as .
Explanation:
There are 3 atoms in NaOH, 1 sodium, 1 oxygen and 1 hydrogen.
There are 3 atoms in H2O, 2 hydrogen and 1 oxygen.
In a reversible reaction, the endothermic reaction absorbs ____________ the exothermic reaction releases.
A. None of these, endothermic reactions release energy
B. more energy than
C. the same amount of energy as
D. less energy than
Answer:
C. the same amount of energy as
Explanation:
Firstly, a chemical reaction can either absorb energy from its surroundings to occur or release energy into its surroundings as a product. The former and latter descriptions are called ENDOTHERMIC and EXOTHERMIC reactions respectively. An exothermic reaction is that which transfers energy, in form of heat, to its surroundings while an Endothermic reaction is that which absorbs energy (heat) from its surroundings.
However, a reversible reaction is that reaction in which the formation of products from reactants and reformation of the reactants from products occur simultaneously. Hence, the products of a reversible reaction can become the reactants and move in the opposite direction. For example:
Reversible reaction: A + B ⇆ C + D means;
A + B → C + D and;
C + D → A + B
In a case whereby the opposite reactions consist of an endothermic and exothermic reactions, the endothermic reaction absorbs the same amount of energy as the exothermic reaction releases.
According to the law of conservation of energy, no energy is lost during a reversible reaction. Hence, in order to achieve an equilibrium, the amount of energy absorbed by the endothermic reaction is the same as the amount of energy released in the opposite exothermic reaction.