the element with highest melting point among Tc, Ag, Rb is Tc that is technetium, while the element which highest melting point among Hg, Os, Ba is Os that is osmium. both of these elements belong to the d block also known as transition elements.
there is no regular trend in the melting point among the d block elements and tungsten is the elements with the highest melting point among the transition elements. the s block elemts on the other hand have relatively low melting points.
Rb and Ba belong to s block thus have lower melting points in comparison to d block elemts like technetium, osmium, silver, and mercury. s block metals are soft and have low melting points due to very week inter-metallic bonding between its atoms.
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A) Calculate the percent ionization of 0.120 MM lactic acid (Ka=1.4×10−4Ka=1.4×10−4).
Express the percent ionization to two significant digits.
B) Calculate the percent ionization of 0.120 M lactic acid in a solution containing 8.0×10−3 M M sodium lactate.
Express the percent ionization to two significant digits.
C) Calculate the pH of a buffer that is 0.120 MM in NaHCO3 and 0.280 M in Na2CO3
Express your answer to two decimal places.
D) Calculate the pH of a solution formed by mixing 65 mL of a solution that is 0.24 M in NaHCO3 with 75 mL of a solution that is 0.17 M in Na2CO3
Express your answer to two decimal places.
pH of the solution using the Henderson-Hasselbalch equationpH = pKa + log([base]/[acid + base])pKa = 10.33 + log([CO2]/[HCO3-])For NaHCO3, [CO2] = 0.0004 M and [HCO3-] = 0.2025 MFor Na2CO3, [CO2] = 0.0004 M and [HCO3-] = 0.0 pH = 10.33 + log((0.2025)/(0.0004 + 0.2025))pH = 9.25 (Answer)
Percent ionization of 0.120 MM lactic acid(Ka=1.4×10−4): Percent ionization refers to the degree of ionization of a weak electrolyte in solution. It is calculated by taking the ratio of the concentration of ionized species to the initial concentration of the compound multiplied by 100.The formula for percent ionization is:% Ionization = (concentration of H+ ions / initial concentration of lactic acid) × 100Given that, concentration of lactic acid = 0.120 MMInitial concentration of lactic acid = 0.120 MMConcentration of H+ ions = x (as lactic acid is weak electrolyte and it is assumed that x moles of lactic acid ionizes into x moles of H+ and x moles of lactate)Ka of lactic acid = 1.4×10−4Kw/Ka = 1.0×10-14/1.4×10-4 = 7.14×10^-11Now, write the expression for Ka of lactic acid and solve for x Ka = [H+][Lactate]/[Lactic acid]1.4×10^-4 = x² / (0.120 – x)x = 3.87 × 10^-3[Moles of H+]/[Initial moles of lactic acid] x 100 = Percent ionization = 3.87×10^-3/0.120 × 100 = 3.22% (Answer)B) Calculation of percent ionization of 0.120 M lactic acid in a solution containing 8.0×10−3 M M sodium lactate:Given that, concentration of lactic acid = 0.120 MConcentration of sodium lactate = 8.0×10−3 MInitial concentration of lactic acid = 0.120 – 8.0×10−3 = 0.112 MConcentration of H+ ions = x (as lactic acid is weak electrolyte and it is assumed that x moles of lactic acid ionizes into x moles of H+ and x moles of lactate)Ka of lactic acid = 1.4×10−4Kw/Ka = 1.0×10-14/1.4×10-4 = 7.14×10^-11Now, write the expression for Ka of lactic acid and solve for xKa = [H+][Lactate]/[Lactic acid]1.4×10^-4 = x² / (0.112 – x)x = 2.73 × 10^-3[Moles of H+]/[Initial moles of lactic acid] x 100 = Percent ionization = 2.73×10^-3/0.120 × 100 = 2.28% (Answer)C) Calculation of pH of a buffer that is 0.120 MM in NaHCO3 and 0.280 M in Na2CO3:Given that, concentration of NaHCO3 = 0.120 MMConcentration of Na2CO3 = 0.280 MNow, calculate the pKa of the H2CO3/HCO3- buffer system:pKa = pH + log([HCO3-]/[H2CO3])pKa = 10.33 + log(0.280/0.120) = 10.72[HCO3-]/[H2CO3] = antilog (pKa - pH) = antilog (10.72 - 10.33) = 3.65Buffer capacity (ß) = (Change in base/Change in pH) ß = (0.120 × (3.65 + 1))/(1.5 × (10^-5)) = 11680pH = pKa + log([Salt]/[Acid])pH = 10.72 + log(0.280/0.120) = 10.97Answer: 10.97D) Calculation of pH of a solution formed by mixing 65 mL of a solution that is 0.24 M in NaHCO3 with 75 mL of a solution that is 0.17 M in Na2CO3:Step 1: Calculation of moles of NaHCO3 in the first solutionMoles of NaHCO3 = Molarity × Volume (L)Moles of NaHCO3 = 0.24 × (65/1000) = 0.0156Step 2: Calculation of moles of Na2CO3 in the second solutionMoles of Na2CO3 = Molarity × Volume (L)Moles of Na2CO3 = 0.17 × (75/1000) = 0.01275Step 3: Calculation of total moles of HCO3- and CO32-Total moles of HCO3- and CO32- = Moles of NaHCO3 + Moles of Na2CO3Total moles of HCO3- and CO32- = 0.0156 + 0.01275 = 0.02835Step 4: Calculation of new concentration of HCO3- and CO32- after the two solutions are mixedNew concentration of HCO3- and CO32- = Total moles of HCO3- and CO32- / Total volume (L)Total volume = 65/1000 + 75/1000 = 0.14 LNew concentration of HCO3- and CO32- = 0.02835 / 0.14 = 0.2025 MStep 5: Calculation of pH of the solution using the Henderson-Hasselbalch equationpH = pKa + log([base]/[acid + base])pKa = 10.33 + log([CO2]/[HCO3-])For NaHCO3, [CO2] = 0.0004 M and [HCO3-] = 0.2025 MFor Na2CO3, [CO2] = 0.0004 M and [HCO3-] = 0.0 pH = 10.33 + log((0.2025)/(0.0004 + 0.2025))pH = 9.25 (Answer)
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Matthew was cleaning his car on a very hot summer day. He left the cleaning spray he had bought, and was using, on the driveway in the intense heat and the can exploded. Why did this happen?
Answer: The cleaning spray might have containing alcohol.
Explanation:
Some alcohol have the tendency to give an explosive effect on heating. According to the given situation, if the cleaning fluid is containing alcohol and when it had been exposed to air, oxygen and sun heat it will become unstable by producing peroxides which can explode the can in which they have been stored. So, in the given situation, the cleaning spray containing alcohol will explode due to intense heat.
The Ksp value for strontium fluoride, SrF2, is 2.6 x 10-9. What is the molar solubility of strontium fluoride?
The molar solubility of strontium fluoride is 1.11 × 10⁻³ M.
The Ksp value for strontium fluoride, SrF2, is 2.6 × 10⁻⁹. The molar solubility of strontium fluoride, we use the equation for the solubility product constant (Ksp). Ksp = [Sr²⁺] [F⁻]² Ksp is the product of the concentrations of the dissolved ions, each raised to the power of its stoichiometric coefficient. The balanced equation for the dissociation of strontium fluoride is as follows:SrF₂(s) ⇌ Sr²⁺(aq) + 2 F⁻(aq)The molar solubility of strontium fluoride is represented by "s," so we will substitute "s" into the concentrations of the dissolved ions as shown below:Ksp = [Sr²⁺] [F⁻]²2.6 × 10⁻⁹ = s × (2s)²= 4s³Solving for "s" gives us the molar solubility of strontium fluoride:s = ∛(2.6 × 10⁻⁹ / 4)= 1.11 × 10⁻³ MTherefore, the molar solubility of strontium fluoride is 1.11 × 10⁻³ M.
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a chemist dilutes 2.0 l of a 1.5 m solution with water until the final volume is 6.0 l. what is the new molarity of the solution?
The new molarity of the solution is 0.5 M after diluting 2.0 L of a 1.5 M solution with water until the final volume is 6.0 L.
To find the new molarity of the solution, we can use the formula:
M1V1 = M2V2
Where:
M1 = initial molarity of the solution
V1 = initial volume of the solution
M2 = final molarity of the solution
V2 = final volume of the solution
Given:
M1 = 1.5 M
V1 = 2.0 L
V2 = 6.0 L
Let's substitute the values into the formula and solve for M2:
M1V1 = M2V2
(1.5 M)(2.0 L) = M2(6.0 L)
3.0 mol = M2(6.0 L)
Now, let's isolate M2 by dividing both sides of the equation by 6.0 L:
M2 = 3.0 mol / 6.0 L
M2 = 0.5 M
Therefore, the new molarity of the solution is 0.5 M after diluting 2.0 L of a 1.5 M solution with water until the final volume is 6.0 L.
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Can someone please help me with 1,2,3 please
.Calculate the pH of a solution that contains 3.25 M HCN (Ka = 6.2 × 10–10), 1.00 M NaOH and 1.50 MNaCN.
Question 14 options:
A) 8.28
B) 7.46
C) 9.25
D) 8.86
E) none of these
E) The pH of the solution is approximately 13.398, and none of the given options (A, B, C, D) matches this value.
To calculate the pH of the solution, we need to consider the ionization of HCN and the hydrolysis of CN-. First, we calculate the concentration of H+ ions from the ionization of HCN using the Ka value.
Then, we consider the hydrolysis of CN- to calculate the concentration of OH- ions. Finally, we use the concentration of H+ and OH- ions to determine the pH.
Given:
HCN concentration = 3.25 M
Ka value =[tex]6.2 * 10^ - 10[/tex]
NaOH concentration = 1.00 M
NaCN concentration = 1.50 M
1. Calculate the concentration of H+ ions from the ionization of HCN:
[H+] = √(Ka * [HCN])
[tex][H+] = \sqrt(6.2 * 10^-10 * 3.25)[/tex]
[tex][H+] = 1.41 * 10^-5 M[/tex]
2. Calculate the concentration of OH- ions from the hydrolysis of CN-:
[OH-] = [NaOH] + [NaCN]
[OH-] = 1.00 + 1.50
[OH-] = 2.50 M
3. Calculate the pOH using the concentration of OH- ions:
pOH = -log10([OH-])
pOH = -log10(2.50)
pOH ≈ 0.602
4. Calculate the pH using the concentration of H+ ions:
pH = 14 - pOH
pH = 14 - 0.602
pH ≈ 13.398
Therefore, the pH of the solution is approximately 13.398. None of the given options (A, B, C, D) matches this value.
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The following disubstituted cyclohexane, drawn in a Newman projection, was shown to have moderate antiviral activity (a) As depicted above, is the adenine group (highlighted) occupying an axial or an equatorial position? Is the CHOH group occupying an axial or an equatorial position? (b) Convert the Newman projection into a bond-line chair form
In the Newman projection, the adenine group is in the axial position, while the CHOH group is in the equatorial position. This arrangement suggests that the adenine group is pointing upward and away from the ring, while the CHOH group is pointing outward and slightly downward.
Converting the Newman projection into a bond-line chair form involves visualizing the cyclohexane ring in a chair conformation. In this conformation, the six carbon atoms form a hexagonal shape, resembling a chair, with alternating axial and equatorial positions. The adenine group, initially in the axial position, is represented as a substituent extending upward from one of the carbons in the ring, while the CHOH group, initially in the equatorial position, is depicted as a substituent extending outward and slightly downward from the ring.
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write any two equations to illustrate that hydrogen gas is a reducing agent
Question Identify the element with the ground state electron configuration [Xe]4f14
5d6
6s2 .
Answer Ir
Ta
Os
Ru
Au
The element with the ground state electron configuration [Xe]4f¹⁴5d⁶6s² is actually Ir, which represents iridium. Option A is correct.
The electron configuration is a representation of how electrons are distributed among the energy levels, subshells, and orbitals within an atom. It follows a specific notation that describes the arrangement of electrons.
The electron configuration indicates that the electrons are arranged in the following manner;
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d⁶
The [Xe] notation represents the electron configuration of the noble gas xenon (Xe), which includes all the electrons up to the 5p level. After the noble gas core, we have 4f¹⁴ 5d⁶, which corresponds to the electron configuration of iridium (Ir).
Hence, A is the correct option.
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--The given question is incomplete, the complete question is
"Identify the element with the ground state electron configuration [Xe]4f¹⁴5d⁶6s². Options; A) Ir B) Ta C) Os D) Ru E) Au."--
What is responsible for moving the water to the ground?
Answer:
Water applied to the surface of a relatively dry soil infiltrates quickly due to the affinity of the soil particles for water. As time passes and the soil becomes wet, the force of gravity becomes the dominant force causing water to move.
Explanation:
Answer:
Gravity
Explanation:
Water applied to the surface of a relatively dry soil infiltrates quickly due to the affinity of the soil particles for water. As time passes and the soil becomes wet, the force of gravity becomes the dominant force causing water to move.
In each of the following reactions, put a square around the substance that is reduced and a circle around the substance that is oxidized in the forward reaction. Label the oxidizing agent (OA) and the reducing agent (RA) in the forward reaction. If the change does not involve redox, write "no redox" instead. a) Zn + 2H+ - H2 + Zn2+ b) NH + H2O NH3 OH c) Br2 + 2 Agl 12 + 2 AgBr d) Pb + PbO2 + 2 SO42- + 4H 2 PbSO4 + 2 H2O (this is the rxn in your car battery) e) 4H + 2 NO3- + Zn Zn2+ + 2 H2O + 2 NO2 f) 2 OH + 2 MnO2 + 3 H2O2 2 Mn04 + 4 H20
a) In the reaction: [tex]Zn + 2H^+ - > H_2 + Zn_2^+[/tex]
The substance that is reduced is Zn (zinc), which gains electrons to form Zn2+.
The substance that is oxidized is H+ (hydrogen), which loses electrons to form H2.
Oxidizing agent (OA): H+
Reducing agent (RA): Zn
b) In the reaction: [tex]NH + H_2O - > NH_3 + OH[/tex]
This reaction does not involve a redox process. It is a simple acid-base reaction where NH acts as a base and H2O acts as an acid.
c) In the reaction: [tex]Br2 + 2 Agl - > 12 + 2 AgBr[/tex]
The substance that is reduced is Br2 (bromine), which gains electrons to form 2 Br-.
The substance that is oxidized is Agl (silver iodide), which loses electrons to form 2 Ag.
Oxidizing agent (OA): Br2
Reducing agent (RA): Agl
d) In the reaction: [tex]Pb + PbO_2 + 2 SO_4^2- + 4H - > 2 PbSO_4 + 2 H_2O[/tex]
The substance that is reduced is [tex]PbO_2[/tex] (lead dioxide), which gains electrons to form [tex]PbSO_4[/tex].
The substance that is oxidized is Pb (lead), which loses electrons to form [tex]PbSO_4[/tex].
Oxidizing agent (OA): [tex]PbO_2[/tex]
Reducing agent (RA): Pb
e) In the reaction: [tex]4H + 2 NO_3- + Zn - > Zn_2+ + 2 H_2O + 2 NO_2[/tex]
The substance that is reduced is [tex]NO_3^-[/tex](nitrate), which gains electrons to form [tex]NO_2[/tex].
The substance that is oxidized is Zn (zinc), which loses electrons to form [tex]Zn_2^+[/tex].
Oxidizing agent (OA): [tex]NO_3^-[/tex]
Reducing agent (RA): Zn
f) In the reaction: [tex]2 OH + 2 MnO_2 + 3 H_2O_2 - > 2 MnO_4^- + 4 H_2O[/tex]
The substance that is reduced is MnO2 (manganese dioxide), which gains electrons to form [tex]MnO_4^-[/tex].
The substance that is oxidized is H2O2 (hydrogen peroxide), which loses electrons to form [tex]H_2O[/tex].
Oxidizing agent (OA): [tex]H_2O_2[/tex]
Reducing agent (RA): [tex]MnO_2[/tex]
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Need help please!! To obtain pure lead, lead (II) sulfide is burned in an atmosphere of pure oxygen. The products of the reaction are lead and sulfur trioxide (SO3). Write a balanced chemical equation for this process. How many grams of lead will be produced if 2.54 grams of PbS is burned with 1.88 g of O2? Express your answer to the correct number of significant figures. Be sure to show all steps completed to arrive at the answer. (Hint: be sure to work the problem with both PbS and O2).
The equation of the reaction is [tex]2PbS + 3O_{2} --- > 2Pb + 2SO_{3}[/tex] and the mass of lead produced is 2.28 g
What is the equation?The term equation is the means by which we could be able to represent what is going on in the reaction system on a piece of paper. Thus, when we write a reaction equation, it is a representation of the process that is going on in the system. By the use of the stoichiometry of the reaction we could obtain the parameters of the equation.
The balanced reaction equation is; [tex]2PbS + 3O_{2} --- > 2Pb + 2SO_{3}[/tex].
Number of moles of lead (II) sulfide = 2.54 grams/239 g/mol = 0.011 moles
Number of moles of oxygen = 1.88 g/32 g/mol = 0.059 moles
If 2 moles of lead (II) sulfide reacts with 3 moles of oxygen
0.011 moles of lead (II) sulfide reacts with 0.011 moles * 3 moles /2 moles
= 0.0017 moles
Hence lead (II) sulfide is the limiting reactant.
If 2 moles of lead (II) sulfide produces 2 moles of lead
Mass of the Lead produced = 0.011 moles * 207 g/mol = 2.28 g
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what reflectivity would be necessary to keep the average temperature exactly at the freezing point? express your answer in percent to two significant figures.
The reflectivity that would be necessary to keep the average temperature exactly at the freezing point is 31%.
Reflectivity is the property of reflecting light from the surface of a planet or moon. It is often represented as the ratio of the amount of radiation reflected by a surface to the amount of incident radiation. The Albedo of Earth is approximately 30%. Albedo is a measure of the amount of radiation reflected by a surface. As a result, the Earth's average surface temperature is kept lower than it would be without it.
Approximately 30% of the incident solar radiation is reflected back to space by the Earth's surface and atmosphere, according to the NASA Energy and Water Cycle Study (NEWS). Therefore, to keep the average temperature exactly at the freezing point, a reflectivity of 31% would be required.
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what new functional group is formed during an elimination reaction chem 3a berkeley
During an elimination reaction in organic chemistry, a new double bond (π bond) is formed, resulting in the creation of an alkene functional group. This process involves the removal of a leaving group and the adjacent hydrogen atom from a molecule, resulting in the formation of a double bond between the two adjacent carbon atoms.
In elimination reactions, a strong base or acid is often used to abstract the proton from the adjacent carbon atom, generating a carbanion intermediate. The leaving group is then expelled from the molecule, and the carbanion intermediate undergoes a rearrangement to form a more stable carbocation. Finally, the base or another molecule acts as a nucleophile, capturing a proton from the carbocation to form the double bond. This newly formed double bond represents the alkene functional group and is characteristic of elimination reactions in organic chemistry.
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A 9.70-g piece of solid CO2 (dry ice) is allowed to sublime in a balloon. The final volume of the balloon is 1.00 L at 298 K. What is the pressure of the gas?
The pressure of the gas is 5.52 atm
Mass of CO2 (dry ice) = 9.70 gVolume of the balloon after the solid CO2 sublimes = 1.00 LTemperature of the balloon = 298 KWe need to find out the pressure of the gas. The molar mass of CO2 is:Molecular mass of C = 12.01 g/molMolecular mass of O = 15.99 g/molMolecular mass of CO2 = 12.01 + (2 × 15.99) = 44.01 g/molNow, the number of moles of CO2 = mass/molar mass= 9.70/44.01 = 0.220 molThe Ideal Gas Law is represented by the formula PV = nRT,where P = pressureV = volume of the gasn = number of moles of the gasR = gas constant = 0.0821 L atm/(mol K)T = temperature of the gasNow substituting the values in the Ideal Gas Law,we getP = nRT / V= (0.220 mol × 0.0821 L atm/(mol K) × 298 K) / 1.00 LP = 5.52 atmTherefore, the pressure of the gas is 5.52 atm.
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Ammonia, NH3, rapidly reacts with hydrogen chloride, HCl, making ammonium chloride. Write a balanced chemical equation for the reaction. States of matter need not be included. X He 8 Im See Periodic Table See Hint Write and balance the chemical equation for the reaction between carbon monoxide, Cole), and oxygen to form carbon dioxide, Co. Use only integers (not fractions) and be sure to include the states of matter. X X He- Gal
The balanced chemical equation for the reaction between ammonia (NH₃) and hydrogen chloride (HCl) to form ammonium chloride (NH₄Cl) is
NH₃ + HCl → NH₄Cl and for the reaction between carbon monoxide (CO) and oxygen (O₂) to form carbon dioxide is (CO2) is 2CO + O₂ → 2CO₂
One molecule of ammonia (NH₃) reacts with one molecule of hydrogen chloride (HCl) to produce one molecule of ammonium chloride (NH₄Cl). The reaction is a simple acid-base reaction, where the ammonia acts as a base by accepting a proton (H⁺) from the hydrogen chloride, forming the ammonium ion (NH₄⁺) and the chloride ion (Cl⁻).
Two molecules of carbon monoxide react with one molecule of oxygen to produce two molecules of carbon dioxide. The equation is balanced with two carbon atoms, four oxygen atoms, and two oxygen atoms on both sides.
The reaction represents the combustion of carbon monoxide, where carbon monoxide acts as the reducing agent and oxygen acts as the oxidizing agent. The balanced equation shows the conservation of mass, with the same number of atoms on both sides. This reaction is an important process in the combustion of carbon-containing fuels.
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If five gases in a cylinder EACH exert a partial pressure of 2.5 atm, what is the total pressure in the cylinder? Be sure to bubble your answer on the answer sheet.
Answer:
16 atm
Explanation:
I
11122
11 / 22
=>
Which of the following hydrogen ion concentrations represents a solution with acidic
properties?
A
?
1 x 10-8 M
В.
?
1 x 10-2 M
C
1 x 10-11 M
D
1x 10-13 M
Activity Index
A
Answer:
A
Explanation: 11/22
10. Vocabulary Word: region: any large part of the Earth's surface.
Use the vocabulary word in a sentence:
Answer:
Rice is grown in rainy regions.
The river flooded the whole region.
He explored the region around the South Pole.
Explanation:
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A 1.50 L buffer solution is a .250 M HF and .250 M in NaF. Calculate the pH of the solution after the addition of .0500 M NaOH (Ka for HF is 3.5 x 10^-4)
The pH of the solution after the addition of .0500 M NaOH is 12.70.
Buffer solution volume of the buffer solution = 1.50LConcentration of HF = 0.250 M
Concentration of NaF = 0.250 M
After the addition of NaOH
The concentration of NaOH = 0.0500 M
Ka of HF = 3.5 × 10⁻⁴
First of all, we have to determine the moles of HF and NaF initially present in the solution.
Initial moles of HF = Molarity × Volume of solution = 0.250
M × 1.50 L = 0.375 moles
Initial moles of NaF = Molarity × Volume of solution = 0.250 M × 1.50 L = 0.375 moles
After the addition of NaOH, HF, and NaF react with NaOH to form NaF and water as shown below.
HF + NaOH → NaF + H₂O(0.250 M) (excess)(0.0500 M) -x x
molarity of NaOH = 0.0500 M - x
[NaOH] = [NaF] = (initial moles of NaF - x)/Volume of solution
= (0.375 - x)/1.50
Initial moles of NaOH = Molarity × Volume of solution = (0.0500 M - x) × 1.50 L = 0.075 - 1.50 x
Initial moles of NaF = Initial moles of NaOH(As they react in 1:1 ratio)= 0.075 - 1.50 x
Initial moles of HF = 0.375 - x
Initial concentration of HF = (0.375 - x)/1.50= (0.250 - x/6)
After the reaction, the concentration of HF and F⁻ will change by the same amount that is - x and + x respectively.
[H⁺] [F⁻]/[HF] = Ka[H⁺] [0.375 + x]/[0.250 - x/6]
= 3.5 × 10⁻⁴[H⁺]
= 3.5 × 10⁻⁴ × (0.375 + x)/(0.250 - x/6)
As the solution is a buffer solution, pH = pKa + log [F⁻]/[HF]
pKa = -log Ka
= -log 3.5 × 10⁻⁴= 3.455
pH = 3.455 + log [0.375/(0.250 - x/6)]
The value of x can be calculated by using the ICE table. The values of [H⁺] and x will be very small as the concentration of NaOH added is very less.
So, x can be neglected.
x = [OH⁻] = 0.0500 M[H⁺] = Kw/[OH⁻] = 1.0 × 10⁻¹⁴/0.0500 M
= 2.0 × 10⁻¹³pH
= -log [H⁺] = -log (2.0 × 10⁻¹³)
= 12.70 (approx)
Therefore, the pH of the buffer solution after the addition of 0.0500 M NaOH is approximately 12.70.
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What is the term for the limited recyclable life of certain materials? o single-stream recycling o closed-loop recycling O dual-stream recycling downcycling
Answer:
There are three main types of recycling: primary, secondary, and tertiary.Single-stream recycling is a system in which all recyclables, including newspaper, cardboard, plastic, aluminum, junk mail, etc., are placed in a single bin or cart for recycling. ... While collections costs are lower with a single stream system, processing costs are much higher.
Explanation:
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What does a negative AH tell about a reaction?
A. The reaction absorbed heat.
B. The reaction has no enthalpy.
C. The reaction is exothermic.
D. The reaction is endothermic.
SUBMIT
Answer:
The reaction is exothermic
Explanation:
How are a moon and an asteroid different? (2 points)
a
A moon revolves around an asteroid, while an asteroid rotates around its axis.
b
A moon revolves around a planet, while an asteroid revolves around a star.
c
A moon revolves around a star, while an asteroid rotates around its axis.
d
A moon rotates around its axis, while an asteroid revolves around a planet.
Answer:
B
Explanation:
Asteroid - A rock that rvolves arounf the sun / star.
Moon - A natural satillite that revolves around earth/ planet.
What happened when you mixed the two substances together? The substances changed into different substances. The substances changed into different substances. The substances did not change into different substances. The substances did not change into different substances. I am not sure if the substances changed into different substances. I am not sure if the substances changed into different substances.
Answer:
is this a poem or something?
A gas mixture contains each of the following gases at the indicated partial pressures: N2, 236 torr ; O2, 159 torr ; and He, 131 torr .
What mass of each gas is present in a 1.10 −L sample of this mixture at 25.0 ∘C?
The mass of each gas present in a 1.10 L sample of the gas mixture at 25.0 °C is as follows:
Mass of N2: 0.0462 gMass of O2: 0.0309 gMass of He: 0.0213 gTo calculate the mass of each gas, we need to use the ideal gas law and the partial pressure of each gas.
First, we calculate the number of moles of each gas using the equation:
n = PV / RT
For N2:
n(N2) = (236 torr * 1.10 L) / (0.0821 L·atm/mol·K * 298.15 K) = 0.0100 moles
For O2:
n(O2) = (159 torr * 1.10 L) / (0.0821 L·atm/mol·K * 298.15 K) = 0.0067 moles
For He:
n(He) = (131 torr * 1.10 L) / (0.0821 L·atm/mol·K * 298.15 K) = 0.0055 moles
Next, we calculate the mass of each gas using their respective molar masses:
Mass = moles * molar mass
For N2:
Mass(N2) = 0.0100 moles * 28.0134 g/mol = 0.280 g ≈ 0.0462 g
For O2:
Mass(O2) = 0.0067 moles * 31.9988 g/mol = 0.216 g ≈ 0.0309 g
For He:
Mass(He) = 0.0055 moles * 4.0026 g/mol = 0.022 g ≈ 0.0213 g
Therefore, the mass of each gas in the given gas mixture is approximately:
N2: 0.0462 gO2: 0.0309 gHe: 0.0213 gLearn more about molar: https://brainly.com/question/837939
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Do the following reactions favor reactants or products at equilibrium?
A. Sucrose (aq) + H2O(l) = Glucose (aq) + fructose (aq) k= 1.4 × 10^5
B. NH3 (aq) + H2O(l) = NH4^+(aq) + OH^-(aq) k= 1.6 × 10^-5
C. Fe2^03(s) + 3 co(g) = 2 Fe(s) + 3 co2(g) k( at 727°C)=24.2
A. Sucrose (aq) + H₂O(l) ⇌ Glucose (aq) + Fructose (aq) (k = 1.4 × 10⁵)
B. NH₃ (aq) + H₂O(l) ⇌ NH⁴⁺(aq) + OH⁻(aq) (k = 1.6 × 10⁻¹⁵)
C. Fe₂O₃(s) + 3 CO(g) ⇌ 2 Fe(s) + 3 CO₂(g) (k at 727°C = 24)
A. Sucrose (aq) + H₂O(l) ⇌ Glucose (aq) + Fructose (aq) (k = 1.4 × 10⁵)
The high value of the equilibrium constant (k = 1.4 × 10⁵) indicates that the reaction strongly favors the products (glucose and fructose) at equilibrium. This means that at equilibrium, there will be a high concentration of glucose and fructose compared to sucrose and water.
B. NH₃ (aq) + H₂O(l) ⇌ NH₄⁺(aq) + OH⁻(aq) (k = 1.6 × 10⁻⁵)
The low value of the equilibrium constant (k = 1.6 × 10⁻⁵) indicates that the reaction favors the reactants (NH₃ and H₂O) at equilibrium. This means that at equilibrium, there will be a higher concentration of NH₃ and H₂O compared to NH₄⁺ and OH⁻.
C. Fe2O₃(s) + 3 CO(g) ⇌ 2 Fe(s) + 3 CO₂(g) (k at 727°C = 24)
The value of the equilibrium constant (k = 24) does not provide information about whether the reaction favors the reactants or products. To determine which side is favored, one would need to compare the initial concentrations or partial pressures of the reactants and products. However, the presence of the solid Fe2O₃ indicates that it is likely the reactant side (Fe2O₃ and CO) that is favored at equilibrium, as the solid does not contribute to the equilibrium expression.
Overall,
A. The reaction strongly favors the products.
B. The reaction favors the reactants.
C. The information provided is insufficient to determine which side is favored at equilibrium.
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Given the following thermochemical equations:
A(g)→B(g);ΔH=70kJB(g)→C(g);ΔH=−110kJ
Find the enthalpy changes for the following reactions:
a. 3A(g)→3B(g)
b. B(g)→A(g)
c. A(g) →C(g)
The stoichiometric concept can be employed for the 3A(g) → 3B(g) transformation.
How to solveThe enthalpy change for the reaction leading from A(g) to B(g) with a value of ΔH = 70 kJ implies that the corresponding enthalpy change for the conversion of 3A(g) to 3B(g) will be threefold higher, with ΔH = 3 * 70 kJ = 210 kJ.
To determine the enthalpy change for the inverse reaction of A(g) → B(g), we can utilize the knowledge that the enthalpy change has the inverse polarity in the reverse reaction.
The enthalpy change for the conversion of gas B to gas A will result in a decrease of 70 kJ.
We can determine the enthalpy shift for the A(g) → C(g) reaction by merging the provided equations.
By combining the equations A(g) → B(g) with a heat of reaction of 70 kJ and B(g) → C(g) with a heat of reaction of -110 kJ, we can obtain a new equation.
Through this, we are presented with the generalized reaction of converting A into B, which subsequently forms C, accompanied by a change in enthalpy of -40 kJ within the range of 70 kJ-110 kJ.
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which of the following statements are correct if a and c are either both positive?
The main answer is: E. None of the given statements is correct as none accurately describes the correlation between linear combinations of variables.
None of the given statements accurately describes the correlation between linear combinations of variables. In general, the correlation between two linear combinations (aX + b) and (cY + d) cannot be simply expressed as a product of correlations or as the correlation between the original variables X and Y. The correlation between linear combinations depends on the specific values of a, b, c, and d, as well as the correlation between X and Y.
Therefore, none of the given statements are correct in this case.
The complete question should be:
Which of the following statements are correct if a and c are either both positive?
A. Corr(aX + b, cY + d) = ab Corr(X, Y) + bd
B. Corr(aX + b, cY + d) = ab Corr(X, Y)
C. Corr(aX + b, cY + d) = Corr(X, Y)
D. Corr(aX + b, cY + d) = Corr(aX, cY)
E. None of the given statements is correct.
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a) A balloon is filled to a volume of 2.00 L with 4.00 moles of gas at 25 °C. With pressure and temperature held constant, what will be the volume of the balloon if 0.20 moles of gas are released?
b)A weather balloon is filled with 35.0 L helium at sea level where the pressure is 1.00 atm at 20.0 °C. The balloon bursts after ascending until the pressure is 26.0 torr at -50.0 °C. Determine the volume (in L) at which the balloon bursts.
a) 2/1L t will be the volume of the balloon if 0.20 moles of gas are released
b) 1.02L is the volume (in L) at which the balloon bursts.
What is ideal gas law ?
The macroscopic characteristics of ideal gases are related by the ideal gas law (PV = nRT). A gas is considered to be ideal if its particles (a) do not interact with one another and (b) occupy no space (have no volume).
There are four guiding principles that determine if a gas is "ideal": The volume of the gas particles is quite small. The gas particles are of similar size and do not interact with one another through intermolecular forces (attraction or repulsion). The random motion of the gas particles is consistent with Newton's Laws of Motion.
a) PV = nRT
R = 0.082 atm.L/K.mol
V1 = 1.50 L
n1 = 3.00 mol
T1 = 25°C ≅ 298 K
P1 = (RT1n1)/(V1) = (0.082 *298 *4.00 )/(2)
P1 = 48.8 atm
If pressure and temperature remain constant:
T2 = T1 = 298 K
P2 = P1 = 48.8 atm
n2 = 0.20 mol + 4.00 mol = 4.20 mol
V2 = (RT2n2)/P2
V2 = (0.082 * 298 *4.20)/(48.8)
V2 = 2.1 L
b) V1 = 35.0 L
T1 = 20.0 °C = 293K.
P1 = 1.00 atm
P2 = 26.0 torr
T2 = -50.0 °C = 223K
P1V1/T1 = P2V2/T2
1*35/293 = 26*V2/223
V2 = 1.02L
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Part A: Calculate the percent ionization of 0.135 M lactic acid (Ka=1.4×10−4). Express the percent ionization to two significant digits.
Part B: Calculate the percent ionization of 0.135 M lactic acid in a solution containing 6.5×10^−3 M sodium lactate. Express the percent ionization to two significant digits.
1) The percentage ionization is 3.2%
2) The percentage ionization is 21.9%
What is the percent ionization?The percent ionization is primarily used for weak acids and bases, where only a fraction of the compound dissociates. Strong acids and bases, on the other hand, completely dissociate in solution, so the percent ionization is 100%.
We have to use the formula;
α = √ka/C * 100
Where;
α = percent ionization
Ka = The dissociation constant
C = concentration
Then;
α = √1.4×10^−4/0.135 * 100
= 3.2 %
2) α = √6.5×10^−3/0.135 * 100
= 21.9%
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