Answer:
Many chemical reactions are reversible; that is, the products of the reaction can combine to re-form the reactants. An example of a reversible reaction is that of hydrogen with iodine to form hydrogen iodide:
H2(g) + I2(g) 2 HI(g)
We can study this reversible reaction by placing hydrogen and iodine in a reaction vessel and then measuring the concentrations of H2, I2, and HI at various times after the reactants are mixed. Figure 13.8 is a plot of the concentrations of reactants and products of this reaction versus time. The concentration of hydrogen iodide increases very rapidly at first, then more slowly, and finally, after the time indicated by the vertical line marked "Equilibrium," remains constant. Similarly, the concentrations of hydrogen and iodine are large at the start of the reaction but decrease, rapidly at first, and then more slowly. Finally, they, too, become constant.
If this reaction were not reversible, the concentrations of hydrogen and iodine would have continued to decrease and the concentration of hydrogen iodide to increase. This process does not happen. Instead, as soon as any molecules of hydrogen iodide are formed, some decompose into hydrogen and iodine. Two reactions are taking place simultaneously: the formation of hydrogen iodide and its decomposition. When the concentrations of all these components become constant (at the equilibrium point in Figure 13.8), the rate of the forward reaction (H2 + I2 2 HI) must be equal to the rate of the reverse reaction (2 HI H2 + I2). A state of dynamic chemical equilibrium has then been reached, one in which two opposing reactions are proceeding at equal rates, with no net changes in concentration.
PICTURE 13.8
FIGURE 13.8 Concentration changes during the reversible reaction
H2(g) + I2(g) 2 HI as it proceeds toward equilibrium.
We have encountered this criterion for equilibrium before. In the equilibrium between a liquid and its vapor, the rate of vaporization is equal to the rate of condensation. In the equilibrium of a saturated solution with undissolved solute, the rate of dissolution is equal to the rate of precipitation. In the equilibrium of a weak acid with its ions, the rate of dissociation is equal to the rate of recombination. Note that none of these reactions is static: Two opposing changes are occurring at equal rates.
B. The Characteristics of Chemical Equilibrium
1. Equal rates
At equilibrium, the rate of the forward reaction is equal to the rate of the reverse reaction.
2. Constant concentrations
At equilibrium, the concentrations of the substances participating in the equilibrium are constant. Although individual reactant molecules may be reacting to form product molecules and individual product molecules may be reacting to re-form the reactants, the concentrations of the reactants and the products remain constant.
3. No free energy change
At equilibrium, the free energy change is zero. Neither the forward nor the reverse reaction is spontaneous and neither is favored. Consider the ice-water change. Above 0°C, ice melts spontaneously to form liquid water; G for this change is negative. Below 0°C, the change from ice to water is not spontaneous; G is positive. At 0°C, the two states are in equilibrium. The rate of melting is equal to the rate of freezing: the amount of ice and water and the amount of liquid water present remain constant, and the free energy change is zero as long as no energy is added to or subtracted from the mixture.
C. The Equilibrium Constant
In Chapter 12, we introduced the mathematical relationship between the concentrations of the components of an equilibrium, known as the equilibrium constant, Keq. We said that, for the general equation of a reversible reaction
Explanation:
sorry(: hope to help
A chemical reaction involves the reactants A and B, and the product C.
A+B→C
Trial 1 2 3
[A](mol/L) 0.10 0.10 0.20
[B](mol/L) 0.10 0.20 0.10
−Δ[A]Δt(molL s) 3.08×10−9 2.464×10−8 1.232×10−8
Explanation:
a+b =ab
answer
ab added all
is give answer
Is brass a solution:
Answer:
Brass is an alloy, and either a "solid solution".
Alloys in general may be solid solutions or they simply be mixtures
Explanation:
Hope it Helps you!!Calculate the moles of HCl in 15 mL of a 0.50 M solution.
Explanation:
[tex]\tiny\implies Molarity = \dfrac{no. \: of \: moles \: of \: solute \times 1000}{volume \: of \: the \: solution \: (in \: ml)} [/tex]
[tex]\tiny\implies 0.50 = \dfrac{no. \: of \: moles \: of \: solute \times 1000}{15}[/tex]
[tex]\tiny\implies no. \: of \: moles \: of \: solute \times 1000 = 0.50 \times 15[/tex]
[tex]\tiny\implies no. \: of \: moles \: of \: solute \times 1000 = 7.5[/tex]
[tex]\tiny\implies no. \: of \: moles \: of \: solute = \dfrac{7.5}{1000} [/tex]
[tex]\tiny\implies \bf no. \: of \: moles \: of \: solute = 0.075 \: mol[/tex]
0 000
which explains why it is important to eat a full healthy meal before an oron o ping po
Food provides the carbon dioxide that is a product of cellular respiration
Food provides the oxygen that is a product of cellular respiration
Food provides the glucose that is a reactant in cellular respiration.
Food provides the energy that is a reactant in cellular respiration.
Answer:
A healthy diet is essential for good health and nutrition. It protects you against many chronic noncommunicable diseases, such as heart disease, diabetes and cancer. Eating a variety of foods and consuming less salt, sugars and saturated and industrially-produced trans-fats, are essential for healthy diet.
as the solar nebula cooled which compounds were the first to condense from a gas to a solid? Rock water ice or metal
As the solar nebula cooled METAL compounds are the first to condense from a gas to a solid. The solar nebula gave birth to the Solar system.
A solar nebula is a disc-shaped cloud of gases and grain dust, which gave birth to the Sun and planets of the Solar system, approximately 4.6 billion years ago.
The solar nebula is at the beginning a mixture of interstellar gases (hydrogen and helium) and dust grains.
As the solar nebula cools, heavy elements such as metals in the disk condensate into planetesimals.
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Because electron delocalization stabilizes a compound, if the only way electrons can be moved is away from the most electroneagtive atom, that is better than no electron delocalization at all.
a. True
b. False
As electron delocalization stabilizes the compound it is necessary that it takes place for compound to exist , hence the given statement is false.
What is a compound?Compound is defined as a chemical substance made up of identical molecules containing atoms from more than one type of chemical element.
Molecule consisting atoms of only one element is not called compound.It is transformed into new substances during chemical reactions. There are four major types of compounds depending on chemical bonding present in them.They are:
1)Molecular compounds where in atoms are joined by covalent bonds.
2) ionic compounds where atoms are joined by ionic bond.
3)Inter-metallic compounds where atoms are held by metallic bonds
4) co-ordination complexes where atoms are held by co-ordinate bonds.
They have a unique chemical structure held together by chemical bonds .Compounds have different properties as those of elements because when a compound is formed the properties of the substance are totally altered.
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If the pressure of 50.0 mL of oxygen gas at 100°C increases from 735 mm Hg to 925 mm Hg, what is
the final volume? Assume temperature remains constant.
Answer: .039L
Explanation:
an alloy composed of tin, lead, and cadmium is analyzed. the mole ratio of sn:pb is 2.73:1.00, and the mass ratio of pb:cd is 1.78:1.00. what is the mass percent composition of pb in the alloy
This problem is describe the mole-ratio composition of an allow composed by tin, lead and cadmium. Ratios are given as Sn:Pb 2.73:1.00 and Pb:Cd is 1.78:1.00, and we are asked to calculate the mass percent compositon of Pb in the allow.
In this case, according to the given information, it turns out possible realize that the following number of moles are present in the alloy, according to the aforementioned ratios:
[tex]2.73mol Sn\\\\1.00molPb\\\\\frac{1.00molPb*1.00molCd}{1.78molPb}= 0.562molCd[/tex]
Next, we calculate the masses by using each metal's atomic mass:
[tex]m_{Sn}=2.73mol*\frac{118.7g}{1mol}=324.05g\\\\ m_{Pb}=1.00mol*\frac{207.2g}{1mol}=207.2g\\\\m_{Cd}=0.562mol*\frac{112.4g}{1mol}=63.2g[/tex]
Thus, the mass percent composition of each metal is shown below:
[tex]\%Sn=\frac{324.05g}{324.05g+207.2g+63.2g} *100\%=54.5\%\\\\\%Pb=\frac{207.2g}{324.05g+207.2g+63.2g} *100\%=34.9\%\\\\\%Cd=\frac{63.2}{324.05g+207.2g+63.2g} *100\%=10.6\%[/tex]
So that of lead is 34.9 %.
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Answer: Evaporation and sublimation.
Explanation: Evaporation is the process of changing from liquid to gas, and sublimation is the process of changing from solid to gas.
The Law of Conservation of Energy states that Energy can neither be ____________ nor _____________ but only change from one __________ to another.
Answer:
Explanation:
The law of conservation of energy states that energy can neither be created nor destroyed but only changed from one form of energy to another.
The law of conservation of energy states that energy can neither be created nor destroyed but changes from one state to another.
What is law of conservation of energy?The law of conservation of energy states that energy can neither be created nor destroyed it can only be converted from one form of energy to another.According to this, the total energy of the system remains constant.
This statement is also a statement of first law of thermodynamics which is based on energy.Conservation of energy is distinct from conservation of mass as mass and energy are directly proportional which is given the equation, E=mc².
Because of law of conservation of energy the perpetual motion of machine cannot exist. This means that no system without an external source of energy can supply unlimited amount of energy to its surroundings.
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How to find distance from motion graph velocity - time?
Answer:
by finding the slope of tangent (y2 - y1)/(x2 - x1)
Grace wanted to find out the best conditions for growing lettuce plants.
She took 4 trays and planted 8 lettuce plants in each.
The results of her investigation are shown below.
How many days did the investigation last?
Use the table to help you.
Explanation:
the investigation lasts for 7 days.
hope this helps you.
In the following reaction, what is the quantity of heat (in kJ) released when 5.87 moles of CH₄ are burned?
CH₄ (g) + 2 O₂ (g) → CO₂ (g) + 2 H₂O(g) ∆H° = -802 kJ/mol
Taking into account the definition of enthalpy of a chemical reaction, the quantity of heat released when 5.87 moles of CH₄ are burned is 4,707.74 kJ.
The enthalpy of a chemical reaction as the heat absorbed or released in a chemical reaction when it occurs at constant pressure. That is, the heat of reaction is the energy that is released or absorbed when chemicals are transformed into a chemical reaction.
The enthalpy is an extensive property, that is, it depends on the amount of matter present.
In this case, the balanced reaction is:
CH₄ (g) + 2 O₂ (g) → CO₂ (g) + 2 H₂O(g)
and the enthalpy reaction ∆H° has a value of -802 kJ/mol.
This equation indicates that when 1 mole of CH₄ reacts with 2 moles of O2, 802 kJ of heat is released.
When 5.87 moles of CH₄ are burned, then you can apply the following rule of three: if 1 mole of CH₄ releases 802 kJ of heat, 5.87 moles of CH₄ releases how much heat?
[tex]heat=\frac{5.87 molesof CH_{4}x802 kJ}{1 mol of CH_{4} }[/tex]
heat= 4,707.74 kJ
Finally, the quantity of heat released when 5.87 moles of CH₄ are burned is 4,707.74 kJ.
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Answer:
dog dog im not gon hold u we kinda screwed
Construct a conclusion using the claim, evidence and reasoning format to explain the typical properties observed by ionic and covalent compounds.
Answer:
The key to understanding why ionic and covalent compounds have different properties from each other is understanding what's going on with the electrons in a compound. Ionic bonds form when atoms have different electronegativity values from each other. When the electronegativity values are comparable, covalent bonds form.
But, what does this mean? Electronegativity is a measure of how easily an atom attracts bonding electrons. If two atoms attract electrons more or less equally, they share the electrons. Sharing electrons results in less polarity or inequality of charge distribution. In contrast, if one atom attracts bonding electrons more strongly than the other, the bond is polar.
Ionic compounds dissolve in polar solvents (like water), stack neatly on each other to form crystals, and require a lot of energy for their chemical bonds to break. Covalent compounds can be either polar or nonpolar, but they contain weaker bonds than ionic compounds because they are sharing electrons. So, their melting and boiling points are lower and they are softer.
I hope this helps have a great day :)
Which statement best describes a mechanical wave?
Answer:
A mechanical wave is a wave that is an oscillation of matter, and therefore transfers energy through a medium.
Explanation:
While waves can move over long distances, the movement of the medium of transmission—the material—is limited. Therefore, the oscillating material does not move far from its initial equilibrium position.
--------------
hope this helped!
✼-answers by brookeangelx
The wave transmits energy from one point to another in the form of signals. Some waves require a medium for propagation while some others does not require a medium for the propagation.
What is a mechanical wave?The mechanical wave is defined as the wave which involves the oscillation of matter and it is responsible for the transfer of energy through a medium. These types of waves does not need a medium for propagation.
The mechanical waves cannot travel through vacuum. Some of the examples of mechanical waves are sound waves, water waves, seismic waves, etc. These waves are not capable of transmitting its energy through a vacuum.
The sound wave is a mechanical wave and the medium which it propagates can be solid, liquid or gas. It can travel fastest in solids and slower in gases.
Thus mechanical wave is an oscillation of matter.
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Dissolution of KOH, ΔHsoln:
KOH(s) → KOH(aq) (10.1)
Neutralization of solid KOH, ΔHneut:
KOH(s) + HCl(aq) → H2O(l) + KCl(aq) (10.2)
1) Using Hess's law, show how to combine Reaction 10.1 and Reaction 10.2 to give
KOH(aq) + HCl(aq) → H2O(l) + KCl(aq) (10.3)
2)How should ΔHsoln and ΔHneut be combined (mathematically) to give the change in enthalpy for Reaction 10.3, ΔH?
Using Hess's law we found:
1) By adding reaction 10.2 with the reverse of reaction 10.1 we get reaction 10.3:
KOH(aq) + HCl(aq) → H₂O(l) + KCl(aq) ΔH (10.3)
2) The ΔHsoln must be subtracted from ΔHneut to get the total change in enthalpy (ΔH).
The reactions of dissolution (10.1) and neutralization (10.2) are:
KOH(s) → KOH(aq) ΔHsoln (10.1)
KOH(s) + HCl(aq) → H₂O(l) + KCl(aq) ΔHneut (10.2)
1) According to Hess's law, the total change in enthalpy of a reaction resulting from differents changes in various reactions can be calculated as the sum of all the enthalpies of all those reactions.
Hence, to get reaction 10.3:
KOH(aq) + HCl(aq) → H₂O(l) + KCl(aq) (10.3)
We need to add reaction 10.2 to the reverse of reaction 10.1
KOH(s) + HCl(aq) + KOH(aq) → H₂O(l) + KCl(aq) + KOH(s)
Canceling the KOH(s) from both sides, we get reaction 10.3:
KOH(aq) + HCl(aq) → H₂O(l) + KCl(aq) (10.3)
2) The change in enthalpy for reaction 10.3 can be calculated as the sum of the enthalpies ΔHsoln and ΔHneut:
[tex] \Delta H = \Delta H_{soln} + \Delta H_{neut} [/tex]
The enthalpy of reaction 10.1 (ΔHsoln) changed its sign when we reversed reaction 10.1, so:
[tex] \Delta H = \Delta H_{neut} - \Delta H_{soln} [/tex]
Therefore, the ΔHsoln must be subtracted from ΔHneut to get the total change in enthalpy ΔH.
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Which of the following is NOT a type of evidence indicating that a chemical change has occurred? *
- fizzing/bubbling
- heat is released
- solubility
- sound is given off
Answer:
sound is given off
Explanation:
due to a number of scientific research sound that is given off of an object is not due to a chemical reaction.
What does a chemical reaction tell us?
Answer:
A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products. The properties of the products are different from those of the reactants.
I hope this helps.
A car is traveling 70km in 45 minutes. How many miles an hour is the car traveling?
52
Explanation:
70x45÷60= 52
I hope this is helpful
1 ton of methanol are accidentally discharged into a lake. By how much is the biological oxygen demand of this water increased
The biological Oxygen demand of the lake is increased by 1.5 ton.
Discussion:
The reaction of methanol with Oxygen is as follows;
2CH3OH + 3O2 ==> 2CO2 + 4H2O.In the reaction above; Since Methanol, CH3OH and Oxygen, O2 have the same molar mass; 32.
Therefore we can say since;
2 moles of CH3OH requires 3 moles of O2.
Therefore, 1 ton of methanol will require 1.5 ton of oxygen.
The biological Oxygen demand of the water is therefore increased by 1.5 ton as this is the amount of Oxygen consumed by the ethanol.
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A metal (FW 241.5 g/mol) crystallizes into a face-centered cubic unit cell and has a radius of 1.92 Angstrom. What is the density of this metal in g/cm3
This problem provides the molar mass and radius of a metal that has an FCC unit cell and the density is required.
Firstly, we begin with the formula that relates the aforementioned variables and also includes the Avogadro's number and the volume of the unit cell:
[tex]\rho=\frac{Z*M}{V*N_A}[/tex]
Whereas Z stands for the number of atoms in the unit cell, M the molar mass, V the volume and NA the Avogadro's number. Next, since FFC is able to hold 4 atoms and M and NA are given. Next, we calculate the volume of the atom in the unit given the radius in meters:
[tex]V=a^3=(2*1.92x10^-10m*\sqrt{2} )^3=1.60x10^{-28}m^3/atom[/tex]
And finally the required density in g/cm³:
[tex]\rho=\frac{4*241.5g/mol}{1.60x10^{-28}m^3/atom*6.022x10^{23}atom/mol} \\\\\rho=10025739g/m^3=10.03 g/cm^3[/tex]
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https://brainly.com/question/12977980https://brainly.com/question/13110055 What is the mass of 8 moles of sodium chloride?
468 g
4.68 9
46.8 g
4.689 mol
Please answer
I'll mark BRAINLIST
Answer:
468 g _______________________
The mass of 8 moles of sodium chloride is 468 grams. Therefore, option A is correct.
Molar mass, also known as molecular weight, is the mass of one mole of a substance. It is typically expressed in grams per mole (g/mol). Molar mass is calculated by summing the atomic masses of all the atoms in a molecule.
To calculate the mass of a substance, multiply the number of moles by the molar mass of the substance. The molar mass of sodium chloride (NaCl) is approximately 58.44 grams per mole.
The mass of 8 moles of sodium chloride:
Mass = Number of moles × Molar mass
Mass = 8 moles × 58.44 g/mol
Mass = 467.52 grams
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what is the best way to make a supersaturated solution?
A: Heat the solution
B: Stir the Solution
C: Evaporate the solution
D: Cool the solution
Answer:
heat the solution
Explanation:
i think
Answer:
The way to make a supersaturated solution is to add heat, but just a little heat won't do the job. You have to heat the water close to the boiling point. When the water gets this hot, the water molecules have more freedom to move around, and there is more space for solute molecules between them.
How many moles of c3h6will be consumed when 4.11 mol of co2 are produced in the following equation 2c3h6 +9o2 - 6co2 + 6H2o
Answer: a.1.37 b.4.11 c.6.00 d.12.3
Explanation:
Plaseee ASAP
In an experiment hydrochloric acid is added drop by drop to solid sodium sulfite (Na2SO3). A gas is evolved and collected. Half of the collected gas is added to Lugol solution (I2 dissolved in KI solution), the other half of the gas is added to hydrogen sulfide solution. Write the equation of the reactions, discuss the observations that can be seen during the reactions and explain the changes. In your answer, also discuss the followings:
a) What gas is liberated during the reaction between HCl and Na2SO3? Why can it be liberated this way? Write an equation for the reaction.
b) What ability of the gas is
demonstrated in the reactions with Lugol solution and with H2S? Write equations and use oxidation numbers to prove it. What makes it possible for the substance to act differently in the two reactions?
c) What other properties of the gas evolved can you recall?
d) What are the environmental implications of the gas evolved? Write the appropriate equation for the reaction.
SO2 acts both as an oxidizing and a reducing agent depending on the conditions of the reaction. It also leads to acid rain.
The reaction of HCl with Na2SO3 occurs as follows;
Na2SO3 + 2HCl ------> 2NaCl + SO2 + H2O
The gas evolved in the reaction is SO2. It is liberated because sulfites react with acids to liberate sulfur IV oxide.
The ionic equation of the reaction is; [tex]SO3^2-(aq) + 2H^+(aq) ----> SO2(g) + H2O(l)[/tex]
The reaction of SO2 with Lugol solution occurs as follows;
SO2 +I2 + 2H20→ H2SO4 + 2HI. This demonstrates oxidation because sulfur is oxidized from +4 to +6 state from left to right. This shows SO2 as a reducing agent.
With H2S, the gas reacts as follows;
2H2S + SO2 → 3S (s) + 2H2O
The oxidation number of sulfur decreases from +4 to zero. This demonstrates the gas as an oxidizing agent. SO2 can act as oxidizing or reducing agent because it can change its oxidation state to +6(oxidation) by electron loss or gain electrons to decrease its oxidation state as low as -2.
The gas SO2 is an acid gas. It dissolves in water to yield an acid solution. Also SO2 is a bleaching agent. The major environmental impact of SO2 is that it leads to acid rain as follows; 2SO2 + O2 + 2H2O⇌2H2SO4.
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Fill in the left side of this equilibrium constant equation for the reaction of benzoic acid with water
Answer:
C6H5CO2H (aq) + H2O (l) _C6H5CO2- + H3OFind the volume of 0.170 M sulfuric acid necessary to react completely with 72.2 g sodium hydroxide.
The volume of sulphuric acid, H₂SO₄ needed for the complete reaction with 72.2 g of sodium hydroxide, NaOH is 5.31 L
We'll begin by calculating the number of mole in 72.2 g of NaOH. This can be obtained as follow:
Mass of NaOH = 72.2 g
Molar mass of NaOH = 23 + 16 + 1 = 40 g/mol
Mole of NaOH =?Mole = mass / molar mass
Mole of NaOH = 72.2 / 40
Mole of NaOH = 1.805 mole Next, we shall determine the number of mole of H₂SO₄ needed to react with 1.805 mole of NaOH.2NaOH + H₂SO₄ —> Na₂SO₄ + 2H₂O
From the balanced equation above,
2 moles of NaOH reacted with 1 mole of H₂SO₄.
Therefore,
1.805 mole of NaOH will react with = 1.805 / 2 = 0.9025 mole of H₂SO₄.
Finally, we shall determine the volume of H₂SO₄.Mole of H₂SO₄ = 0.9025 mole
Molarity of H₂SO₄ = 0.170 M
Volume of H₂SO₄ =?Volume = mole / Molarity
Volume of H₂SO₄ = 0.9025 / 0.170
Volume of H₂SO₄ = 5.31 LThus, the volume of H₂SO₄ needed for the reaction is 5.31 L
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Three test tubes contain aqueous hydrogen sulfide, aqueous sulfur-dioxide and Lugol reagent. By mixing any two of the three test tubes, identify their contents. Explain, stating reasons, how you arrive at your conclusions. Write equations whenever applicable.
Answer:
Initial rate experiments
The simplest initial rate experiments involve measuring the time taken for some recognizable event to happen early in a reaction. This could be the time required for 5 cm3 of gas to be produced, for a small, measurable amount of precipitate to form, or for a dramatic color change to occur. Examples of these three indicators are discussed below.
The concentration of one of the components of the reaction could be changed, holding everything else constant: the concentrations of other reactants, the total volume of the solution and the temperature. The time required for the event to occur is then measured. This process is repeated for a range of concentrations of the substance of interest. A reasonably wide range of concentrations must be measured.This process could be repeated by altering a different property.
Explanation:
I don't think so if this is the answer. if not ok sorry
Compare the alkali metals and alkaline earth metals with respect to (i) Ionization enthalpy (ii) basicity of oxides (iii) solubility of hydroxide
Answer:
Ionization enthalpy
Explanation:
that should be right
