Answers
Answer:
The correct answer is: pH = 12.73
Explanation:
The neutralization reaction between HCl and KOH is given by the following chemical equation:
HCl + KOH ⇒ KCl + H₂O
Since HCl is a strong acid and KOH is a strong base, HCl is completely dissociated into H⁺ and Cl⁻ ions, whereas KOH is dissociated completely into K⁺ and OH⁻ ions.
For acids, the number of equivalents is given by the moles of H⁺ ions (in this case: 1 equivalent per mol of HCl). For bases, the number of equivalents is given by the moles of OH⁻ ions (in this case: 1 equivalent per mol of KOH).
The H⁺ ions from HCl will react with OH⁻ ions of KOH to give H₂O. The pH is calculated from the difference between the equivalents of H⁺ and OH⁻:
equivalents of H⁺= volume HCl x Molarity HCl
= (15.0 mL x 1 L/1000 mL) x 0.100 mol/L
= 1.5 x 10⁻³ eq H⁺
equivalents of OH⁻= volume KOH x Molarity KOH
= (50.0 mL x 1 L/1000 mL) X 0.100 mol/L
= 5 x 10⁻³ eq OH⁻
There are more OH⁻ ions than H⁺ ions. The excess of OH⁻ (that did not react with H⁺ ions) is calculated as follows:
OH⁻ ions= (5 x 10⁻³ eq OH⁻) - (1.5 x 10⁻³ eq H⁺) = 3.5 x 10⁻³ eq OH⁻= 3.5 x 10⁻³ moles OH⁻
As the volumes of the solutions are additive, the total volume of the solution is:
V= 15.0 mL + 50.0 mL = 65.0 mL= 0.065 L
So, the concentration of OH⁻ ions in the solution is given by:
[OH⁻] = moles OH⁻/V= (3.5 x 10⁻³ moles OH⁻)/0.065 L = 0.054 mol/L = 0.054 M
From [OH⁻], we can calculate pOH:
pOH = -log [OH⁻] = -log (0.054) = 1.27
Finally, we know that pH + pOH= 14; so we calculate pH:
pH= 14 - pOH = 14 - 1,27 = 12.73
Related Questions
Calculate the wavelength of the yellow light emitted by a sodium lamp if the frequency of the radiation is 5.09 × 1014 Hz (5.09 × 10141/s).
Answers
Answer:
λ = 0.58×10⁻⁶ m
Explanation:
Given data:
Wavelength of yellow light = ?
Frequency of yellow light = 5.09 ×10¹⁴ s⁻¹
Solution:
Formula:
Speed of light = frequency × wavelength
Speed of light = 3×10⁸ m/s
by putting values,
3×10⁸ m/s = 5.09 ×10¹⁴ s⁻¹ × λ
λ = 3×10⁸ m/s / 5.09 ×10¹⁴ s⁻¹
λ = 0.58×10⁻⁶ m
Taking into account the definition of wavelength, frecuency and propagation speed, the wavelength of the yellow light is 5.89×10⁻⁷ m.
Wavelength
Wavelength is the minimum distance between two successive points on the wave that are in the same state of vibration. It is expressed in units of length (m).
FrequencyFrequency is the number of vibrations that occur in a unit of time. Its unit is s⁻¹ or hertz (Hz).
Propagation speedThe propagation speed is the speed with which the wave propagates in the medium, that is, it is the magnitude that measures the speed at which the wave disturbance propagates along its displacement.
The propagation speed relate the wavelength (λ) and the frequency (f) inversely proportional using the following equation:
v = f * λ
All electromagnetic waves propagate in a vacuum at a constant speed of 3x10⁸ m/s, the speed of light.
This caseIn this case, you know:
v=3x10⁸ m/s f= 5.09×10¹⁴ Hz λ= ?Replacing:
3x10⁸ m / s= 5.09×10¹⁴ Hz× λ
Solving:
λ= 3×10⁸ m/s ÷ 5.09×10¹⁴ Hz
λ=5.89×10⁻⁷ m
In summary, the wavelength of the yellow light is 5.89×10⁻⁷ m.
Learn more:
brainly.com/question/2232652?referrer=searchResults brainly.com/question/7321084?referrer=searchResults brainly.com/question/14946166?referrer=searchResultsthe color of an object that absorbs all colors except red
Answers
Answer:
The color black absorbs most colors, while white reflects most colors.
I need number 4 I need to know what to do
Answers
A nurse must administer 160 micrograms of atropine sulfate. The drug is available in solution form. The concentration of the atropine sulfate solution is 200 micrograms per milliliter. How many milliliters should be given?
Answers
Amount of drug = concentration x volume
where concentration is the amount of drug per unit volume, and volume is the amount of solution to be given.
Rearranging the formula, we can solve for the volume:
Volume = Amount of drug / concentration
Substituting the given values:
Volume = 160 micrograms / 200 micrograms per milliliter
Volume = 0.8 milliliters
Therefore, the nurse should administer 0.8 milliliters of the atropine sulfate solution.
please help :(
i have no idea what this even means lol
Answers
Here are the answers for A and B.
Answer:
(a) 80% are metals.
(b) (1.) Metals are malleable and ductile. (2.) Metals are dense.
Explanation:
(a) If you look at the picture, there are faint lines dividing the circle into ten parts. Metals take up 8 sections and non-metals take up 2. This means that the number of metals on the periodic table takes up 80% and non-metals take up 20%.
(b) There are many physical properties of metals, but two of them are that metals are malleable & ductile (these relate to how metal can be shaped) and that metals are dense (density = mass ÷ volume).
A chunk of unidentified element, (element "X"), is reacted with nitrogen to form an ionic compound with the chemical formula X3N2. Which of the following elements is the most likely identity of X? a. Se b. Ba c. K d. Al e. Cl
Answers
The correct answer is b. Ba.
To determine which element is the most likely identity of X, we can use the valency of nitrogen and the formula of the ionic compound X3N2.
Nitrogen has a valency of 3-, which means it forms an ion with a charge of -3. Therefore, in the ionic compound X3N2, the total charge of the cations (X3+) must be equal to the total charge of the anions (2N3-).
We can write the equation to express this relationship as:
3X+ + 2N3- → X3N2
Since the compound contains three X cations and two N anions, the cation X must have a charge of +2 to balance the overall charge of the compound.
From the list of elements given, only Ba (barium) has a 2+ charge, which makes it the most likely identity of X. Therefore, the correct answer is b. Ba.
What is nitrogen?
It is a nonmetal and makes up about 78% of Earth's atmosphere, by volume. Nitrogen is the most abundant element in Earth's atmosphere and is chemically inert under normal conditions. It is an essential element for life as it is a component of amino acids, proteins, and nucleic acids such as DNA.To know more about nitrogen, click the link given below:
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Help!!!
Question: What is the correct order of the particles that give texture to soil from smallest to largest?
Options:
A: Clay, sand, silt
B: silt, sand, clay
C: clay, silt, sand
D: sand, silt, clay
Answers
The correct order of the particles that give texture to the soil from smallest to largest is clay, silt, and sand; option C.
What is soil texture?Soil texture refers to a physical classification of the component and types of soils based on their physical texture either as coarse or fine particles.
There are several types of soils and these various types of soils have different textures.
The types of soils and their arrangement based on increasing particle size are as follows:
clay soil - this is the finest particle soil typesilt - this is the next soil type in terms of texturesandy soil - this is the largest of the three soil types in terms of size and texture.Learn more about soil texture at: https://brainly.com/question/8513717
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Guysss how to explain nuclear chemistry? And define nuclear chemistry ?
Answers
Answer:
How do amoeba respire.
Define Diffusion.
Look at the attachment below.
Answers
Sally is wrong because copper is less electropositive than hydrogen, thus, can not displace hydrogen from dilute acids.
The reactions to prepare copper (ii) chloride are:
the chlorination of copper sulfide at a high temperature
reaction of copper (ii) oxide with dilute hydrochloric acid
The equations of the given reactions are as follows:CuS + Cl₂ ---> CuCl₂ + SCuO + 2HCl ----> CuCl₂ + H₂O
What are reactive metals?Reactive metals are metals that readily give up their electrons to form positive ions.
Reactive metals displace hydrogen from dilute acids. They are found in group 1A and 2A of the periodic table. Copper is not a reactive metal and will not displace hydrogen from acids.
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Sally is wrong because copper chloride is not made from the reaction of copper and dilute hydrochloric acid.
2. Copper (ii) chloride can be prepared as follows:
reacting copper (ii) oxide with dilute hydrochloric acidsingle replacement reaction of copper sulfide and chlorine gas at a high temperature3. the equations of the reaction are:
CuO + 2HCl ----> CuCl₂ + H₂OCuS + Cl₂ ---> CuCl₂ + SWhat are single replacement reactions?Single replacement reactions are reactions in which a more reactive atom replaces another atom in a compound.
An example of a single replacement reaction is the reaction of chlorine gas with copper sulfide at high temperatures to form copper chloride.
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Match each reaction to its correct type by dragging it to the appropriate box on the left. Click Done to
check your answers. Drag the items on the left to the correct location on the right.
Answers
From the image attached;
Reaction 1 - Oxidation reduction
Reaction 2 - Precipitation reaction
Reaction 3 - Acid base reaction
Reaction 4 - Reaction with oxygen
What is reaction?A reaction is a procedure or an occurrence in which a change takes place, frequently leading to the conversion of one or more compounds into other substances. A chemical reaction, which entails the rupturing and creation of chemical bonds between atoms or molecules, is what is meant when the word "reaction" is used in reference to chemistry.
When reactant molecules collide with enough force and in the right orientation, the current chemical bonds are broken, and new bonds are formed, converting the reactants into products.
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What’s the correct answer
Answers
Answer:
I think it's 2-methylhept-2-ene
Explanation:
Hope this will help and correct me if I'm wrong.
____describes a
solution in which the amount of
solute dissolved in a given amount
of solvent is less than
the solubility limit.
A. Soluble
B. Supersaturated
C. Saturated
D. Unsaturated
Answers
When the maximum amount of solute has been dissolved in a given amount of solvent, we say that the solution is saturated.
Glycolysis is the process by which energy is harvested from glucose by living things. Several of the reactions of glycolysis are thermodynamically unfavorable (nonspontaneous), but proceed when they are coupled with other reactions.
Which of these reactions is (are) unfavorable?
Reaction A: Pi+glucose⟶glucose-6-phosphate+H2OΔG=13.8 kJ/mol
Reaction B: Pi+fructose-6-phosphate⟶fructose-1,6-bisphosphate+H2OΔG=16.3 kJ/mol
Reaction C: ATP+H2O⟶ADP+PiΔG=−30.5 kJ/mol
A. A
B. B
C. C
Which of these reactions can be coupled so that overall reaction is favorable?
A. A and B
B. A and C
C. B and C
What is the net change in free energy if one selection from part (b) is coupled so that the overall reaction is favorable?
Answers
Answer:
1. Options A and B
2. Options B and C
3.. B. Net ∆G = -16.7 KJ/mol; C. Net ∆G = -14.2 KJ/mol
Explanation:
1. The spontaneity of a chemical reaction depends on its standard free energy change, ∆G. If ∆G is negative, the reaction is favourable, but when it is positive, the reaction is unfavorable.
Therefore, since reaction A and B have ∆G to be positive, they are unfavorable
2. Coupling an unfavorable reaction to a favourable reaction can help the reaction to proceed in the forward direction as long as the net free energy change is negative.
Coupling reaction A and C, as well as reaction B and C will make the reactions to become favourable as net ∆G is negative in both instances.
3. A and C: net ∆G = 13.8 - 30.5 = -16.7 KJ/mol
B and C: net ∆G = 16.3- 30.5 = -14.2 KJ/mol
What is the amount of charge on a calcium ion if its neutral atom has lost two valence electrons?
A. 1+
B. 2+
C. 3+
D. 4+
Answers
Answer: B
Explanation: a calcium ion has a charge of +2 because it has 2 more protons than electrons giving it a positive charge instead of neutral or negative.
Hope it will help you
When the nurse administers ethyl chloride to a client, which type of anesthesia is being administered?
Answers
Answer: Topical Anesthesia.
Explanation:
Topical anesthetics are used to treat ailments including small burns, insect bites, poison ivy, poison oak, poison sumac, and minor cuts and scratches that cause discomfort and irritation.
The nerve terminals in the skin are numbed by topical anesthesia. They don't render patients unconscious like general anesthetics used during surgery do. The majority of topical anesthetics are accessible over-the-counter, but your doctor may have specific recommendations for their usage and dosage given your particular medical condition.
What is the binding energy for the nuclide 199F (atomic mass: 18.9984 amu) in MeV per nucleus?
Answers
The binding energy per nucleon for the ¹⁹F nucleon is equal to 7.786 MeV/nucleon.
What is binding energy?Binding energy can be defined as the minimum quantity of energy that is required to remove the particle from the system. Nuclear binding energy can be described as the energy required to dismantle a nucleus of an atom into free neutrons and protons.
The binding energy will be determined from the mass defect. Mass defect is calculated from the difference between the mass observed and the expected combined mass.
Given the mass of the ¹⁹F = 18.9984 a.m.u.
The mass defect for the ¹⁹F can be calculated as:
Δm = \((M _n +M_p) - M_F\)
\(\triangle m =( 9\times 1.0078 + 10 \times 1.0087 )- 18.9984\)
\(\triangle m =0.1588 \;a.m.u.\)
The binding energy for the fluorine can be calculated as:
E = Δmc²
E = 0.1588 × 931.5
E = 147.92 MeV
The binding energy per nucleon of ¹⁹F can be calculated as:
B.E.N. = 147.92/18.9984 = 7.786 MeV per nucleon
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A- slower wind speeds
B- moving onto land
C- cooler water temperature
D- lower central air pressure
Answers
Answer:
D- lower central air pressure
A change in the number of neutrons in an atom will change an isotope. What will happen when the number of protons changes in an atom?
Answers
6) The density of ammonia gas (NHs) in a 6.0 L container at a pressure of 820 mm Hg and a g/L.
Answers
The density of ammonia gas in the 6.0 L container at a pressure of 820 mm Hg is approximately 0.805 g/L.
To determine the density of ammonia gas (NH3) in a 6.0 L container at a pressure of 820 mm Hg, we need to use the ideal gas law equation, which relates pressure, volume, number of moles, and temperature for a given gas.
The ideal gas law equation is:
PV = nRT
Where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.
Since we are given the pressure (820 mm Hg), volume (6.0 L), and assuming standard temperature and pressure (STP), we can use the values for R (0.0821 L·atm/(mol·K)) and convert the pressure to atm by dividing by 760 (1 atm = 760 mm Hg).
820 mm Hg / 760 mm Hg/atm = 1.08 atm
Now we can rearrange the ideal gas law equation to solve for density (d):
d = (P * M) / (RT)
Where M is the molar mass of ammonia (NH3), which is approximately 17.03 g/mol.
Substituting the values, we have:
d = (1.08 atm * 17.03 g/mol) / (0.0821 L·atm/(mol·K) * 298 K)
Simplifying the equation, we find:
d ≈ 0.805 g/L
Therefore, the density of ammonia gas in the 6.0 L container at a pressure of 820 mm Hg is approximately 0.805 g/L.
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The total pressure of gas collected over water is 770.0 mmHg and the temperature is 23.0 degrees Celsius what is the pressure of hydrogen gas formed in mmHg?
Answers
Given that the total pressure of gas collected over water is 770.0 mmHg, we can assume that this gas mixture contains water vapor and hydrogen gas. We need to determine the partial pressure of hydrogen gas in the mixture.
First, we need to determine the vapor pressure of water at the given temperature of 23.0 degrees Celsius. According to a vapor pressure table, the vapor pressure of water at 23.0 degrees Celsius is 21.1 mmHg.
Next, we can use Dalton's Law of Partial Pressures to calculate the partial pressure of hydrogen gas:
Total pressure = Partial pressure of hydrogen gas + Partial pressure of water vapor
770.0 mmHg = Partial pressure of hydrogen gas + 21.1 mmHg
Partial pressure of hydrogen gas = 770.0 mmHg - 21.1 mmHg = 748.9 mmHg
Therefore, the pressure of hydrogen gas formed in the mixture is 748.9 mmHg.
A piece of metal is heated to 250 degrees then placed in a bucket of water with an initial temperature of 15 degrees. After 10 minutes, the system reaches a point of thermal equilibrium. The water is now 22 degrees. Which of the following is the most likely temperature of the piece of metal?
Answers
Answer: 22 degrees
Explanation:
Most of the information in this question is put there to throw you off- the only important piece of information here is the final temperature of the water.
In a system of say 2, like in this example, whichever object has more energy in the form of heat will transfer that heat to the object with lesser heat if there is an available path to transfer heat between them. Once the two objects are at the same temperature, however, heat can not be transferred from one to another since neither object has more heat than the other to transfer- this is thermal equilibrium.
This question tells us that the system is at thermal equilibrium- when both objects are at the same temperature. Given the temperature of one object, the water, we then know the other object, the metal is the same temperature.
Based on a Kc value of 0.250 and the given data table, what are the equilibrium concentrations of XY, X, and Y , respectively?
Answers
From the solution that we have in the question;
The concentration of X and Y is 0.28 MThe concentration of XY is 0.32 MWhat is the equilibrium constant?The equilibrium constant, denoted as K, is a value that quantitatively represents the ratio of the concentrations of products to reactants at equilibrium in a chemical reaction.
It is a fundamental concept in chemical equilibrium.
The value of the equilibrium constant provides valuable information about the position of equilibrium and the relative concentrations of species involved in a chemical reaction.
Kc = [X] [Y]/[XY]
\(0.25 = (0.1 + x)^2/(0.5 - x)\)
\(0.25(0.5 - x) = (0.1 + x)^2\)
\(0.125 - 0.25x =0.01 + 0.2x + x^2\\ x^2 + 0.45x - 0.115 = 0\)
x = 0.18 M
The equilibrium amount of X and Y= 0.28 M and the equilibrium concentration of XY = 0.32 M
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Based on the answer to the question that we have;
A 0.28 M concentration of X and Y exists at equilibriumXY's concentration at equilibrium is 0.32 M.The equilibrium constantThe ratio of the product to reactant concentrations in a chemical reaction at equilibrium is represented quantitatively by the equilibrium constant, abbreviated as K.
It is a cornerstone of the theory of chemical equilibrium.
A chemical reaction's equilibrium position and the relative concentrations of the species involved can both be learned from the equilibrium constant's value.
Kc = [X][Y]/[XY]
\(0.25 = (0.1 + x)^2/(0.5 - x)\\0.25(0.5 - x) = (0.1 +x)^2\\0.125 - 0.25x = 0.01 +0.2x +x^2\\= 0.18 M\)
The equilibrium concentration of;
XY =0.5 - 0.18
=0.32 M
Then the equilibrium amount of
X and Y is
0.1 + 0.18= 0.28 M.
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A beaker weighed 53.10g. To the isolated beaker was added 5.348g of iron pellets and 56.1g of hydrochloride acid. What was the total mass of the beaker and the products after reaction?
Answers
114.5 g is the total mass of the beaker .
Total mass of beaker=53.10g+5.348g+ 56.1g
Total mass=114.5 g
Mass is used in physics to specific inertia, a fundamental function of all remember. basically, it's far a mass of rely's resistance to changing its course or pace in response to the software of a force.
The exchange that an applied force produces is smaller the extra mass a body has. The kilogram, the unit of mass within the international machine of gadgets, corresponds to 6.62607015 1034 joule seconds using Planck's consistent (SI). One joule is produced by way of multiplying one kilogram by means of one rectangular meter per 2d.
The kilogram is decided by genuine measurements of Planck's regular on account that the second one and the meter have formerly been described in phrases of other bodily constants.
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A 300-mg sample of technetium-99m is used for a diagnostic test. If téchnetium-99m has an effective half-life of 4.8 hours, how much of the
technetium-99m remains 96 hours after the test?
Express your answer to two significant figures and include the appropriate units.
Valae
Units
?
Answers
Answer:
i like butting hole
Explanation:
mkrkr
What is the total number of moles of reactants and products in the
chemical reaction listed below:
2 H₂S +30₂2 H₂O + 2 SO₂
Answers
The total number of moles of reactants and products in the chemical reaction given is 9 moles
How do i determine the total number of moles?The total number of mole of reactants and products in the chemical reaction can be obtained as follow:
2H₂S + 3O₂ -> 2H₂O + 2SO₂
The following were obtained from the above equation:
Mole of H₂S = 2 molesMole of O₂ = 3 molesMole of H₂O = 2 molesMole of SO₂ = 2 molesMole of reactants = Mole of (H₂S + O₂) = 2 + 3 = 5 molesMole of products = Mole of (H₂O + SO₂) = 2 + 2 = 4 molesTotal number of moles =?Total number of mole = Mole of reactants + mole of products
Total number of mole = 5 mole + 4 moles
Total number of mole = 9 moles
Thus, we can say that the total number of mole is 9 moles
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How many grams of ammonium sulfate are needed to make a 0.25 M
solution at a concentration of 6 M?
Answers
The amount in grams of ammonium sulfate are needed to make a 0.25L solution at a concentration of 6 M is 198 grams.
How do we calculate grams from moles?Mass (W) in grams from moles (n) of any substance will be calculated by using the below equation as:
n = W/M, where
M = molar mass
And for this question moles will be calculated by using the below formula:
M = n/V, where
M = molarity of the solution = 6M
V = volume of the solution = 0.25 L
On putting values on the above equation, we get
n = (6)(0.25) = 1.5 moles
Now mass of 1.5 moles of ammonium sulfate will be calculated by using the first formula as:
W = (1.5mol)(132g/mol) = 198g
Hence required mass of ammonium sulfate is 198 grams.
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What is the zonecreated if force of separation occurs?
Answers
What is the equilibrium constant for the reaction
SO2(g) + NO2(9) = SO3(g) + NO(g)?
А. Keq: [S03)(S02]
[NO][NO2]
B. Keq: [SO2)(NO2]
[SO3)(NO]
C. Keq: [SO3)3(NO]
[SO2)2(NO2)2
D. Keq: [SO3)(NO]
[SO2]NO2]
Answers
Answer:
D. Keq: [SO3][NO] /[SO2]NO2]
Explanation:
Hello!
In this case, according to the process to set up equilibrium expressions for chemical reactions at equilibrium, we realize we need to write up the concentration of products on top and that of reactants on bottom; thus, for there chemical reaction herein specified, we obtain:
\(Keq=\frac{[SO_3][NO]}{[SO_2][NO_2]}\)
Thereby, the answer is D. Keq: [SO3][NO] /[SO2]NO2].
Best regards!
Answer:
D
Explanation:
WIL GIVE AS MANY POINTS POSSIBLE!!!!!! A. A U.S. state needs to increase its available electricity. Almost half of the state
is covered in desert, and there are strong winds most of the year. There are no
large or fast-moving rivers, and very few crops are grown.
i. Name two renewable energy sources, and state and explain whether the
state should use them based on the description above. (6 points)
1
ii. If the state wants to minimize environmental damage, what energy sources
should it consider using? Explain your position. (2 points)
Answers
it takes specific amount of energy to remove exactly one electron from an atom.
What is electron?
Electron is a stable sub atomic particle with a charge of negative electricity found in all atoms and acting as the primary Carrier of electricity in solid.
1-This is shown by the equation where the orbit of the electron around a proton is equal to the quantum. The quantities energy level, times a wavelength.
2-So this is this equation and then abruptly hypothesis links quantities. Energy states with a standing wave function so as that the energy of the election on increases its orbit must also increase.
3- And as considering the wavelength, we're assuming station is constant. Two pies are the only constants, and they aren't changing. It does.
4-As the energy or quantifies energy level of an electron increases its radius around the nucleus must increase.
5- Also, if its energy level decreases, its radius must also decrease. So this hypothesis ties together quantities, energy levels and the relationship and its relationship with the size of the circumference around it. A nucleus which is also the electron.
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Describe how you would prepare exactly 100 mL of 0.109 M picolinate buffer, pH 5.61. Possible starting materials are pure picolinic acid (pyridine-2-carboxylic acid, FM 123.10), 1.0 M HCl, and 1.0 M NaOH. Place the given steps in order. Not all of the steps will be used.
Answers
Answer:
1.342g of picolinic acid and 6.743mL of 1.0M NaOH diluting the mixture to 100.0mL
Explanation:
The pKa of the picolinic acid is 5.4.
Using Henderson-Hasselbalch formula for picolinic-picolinate buffer:
pH = pKa + log [Picolinate] / [Picolinic]
Where [] could be taken as moles of each species
5.61 = 5.4 + log [Picolinate] / [Picolinic]
0.21 = log [Picolinate] / [Picolinic]
1.62181 = [Picolinate] / [Picolinic] (1)
Now, both picolinate and picolinic acid will be:
0.100L * (0.109mol / L) =
0.0109 moles = [Picolinate] + [Picolinic] (2)
First, as we will start with picolinic acid, we need add:
0.0109 moles picolinic acid * (123.10g/mol) = 1.342g of picolinic acid
Now, replacing (2) in (1):
1.62181 = 0.0109 moles - [Picolinic] / [Picolinic]
1.62181 [Picolinic] = 0.0109 moles - [Picolinic]
2.62181 [Picolinic] = 0.0109 moles
[Picolinic] = 4.157x10⁻³ moles
And:
[Picolinate] = 0.0109 - 4.157x10⁻³ moles =
6.743x10⁻³ molesTo obtain these moles of picolinate ion we need to make the reaction of the picolinic acid with NaOH:
Picolinic acid + NaOH → Picolinate + Water
That means to obtain 6.743x10⁻³ moles of picolinate ion we need to add 6.743x10⁻³ moles of NaOH
6.743x10⁻³ moles of NaOH that is 1.0M are, in mL:
6.743x10⁻³ moles * (1L / 1mol) = 6.743x10⁻³L * 1000 =
6.743mL of the 1.0M NaOH must be addedThus, we obtain the desire moles of picolinate and picolinic acid to obtain the buffer we want, the last step is:
Dilute the mixture to 100mL, the volume we need to prepareFollowing are the calculation to the mass of picolinic acid:
Let pKa of picolinic acid \(= 5.52\)
form the buffer: \(\bold{pH = pKa + \log(\frac{A-}{ HA})}\)
Acid concentration\(= 0.109\)
We will require the conjugate, which would be formed by interaction of picolinic acid and NaOH.
calcultion to the need:
\(pH = pKa + \log(\frac{A-}{ HA})\\\\5.61 = 5.52 + \log(\frac{A-}{ HA})\)
solve for A- by using antilog
\(0.09 = \log(\frac{A-}{ HA})\\\\1.230= \frac{A-}{HA}\)
When
\(HA = 0.109\\\\A- = 0.134\)
If \(V = 100 ml\)then
\(n A- = M\timesV = 0.134 \times 0.1 = 0.0134 \ mol\ of\ A-\)
needed
\(HA + NAOH \to H_2O + Na^+ \ and \ A-\)
therefore,
ratios =1:1
we need 0.0134 mol of NaOH
\(n = M\times V \\\\V = \frac{0.0134}{1} = 0.0134 \ liter \ of\ NaOH\)
but you also want \(0.109 M\) of free picolinic acid so
\(n = M\times V = 0.109\times 0.1 = 0.0109\ mol \ of \ Acid\)
Therefore:
\(n \ acid = 0.0109 + 0.0134\ mol = 0.0243 \ mol\ of \ acid\)
Preparation:
by add volume (19.07) in NaOH
M = 1.0 to the beaker, and by add water until the beaker marks 1 L
Then add 0.0243 mol of picolinic acid
\(\to m = 0.0243 \times 123 = 2.9889\ grams\) of picolinic acid
stir and pH will be that of buffer.
Learn more:
brainly.com/question/17156849