The molar ratio of HPO42- to H2PO4- in a solution is 1.4. Calculate the pH of the solution. Phosphoric acid (H3PO4) is a triprotic acid with 3 pKa values: 2.14, 6.86, and 12.4.
Given is the ratio of conjugate base and conjugate acid of phosphoric acid. pH of a substance is the concentration of the hydrogen ions in its solution and higher this concentration lower is the value of pH.
pKa value is a measure of the strength of acid, it is the negative log of acid dissociation constant Ka.
What is the gravitational potential energy of a 1500-kg truck resting on top of a 550-m hill on earth?( earth’s gravitational pull is 9.8m/s2).
Answer:
E = 8085 kJ
Explanation:
Given that,
The mass of a truck, m = 1500 kg
Height, h = 550 m
We need to find the gravitational potential energy of the truck. It can be calculated as follows :
[tex]E=mgh[/tex]
Put all the values,
[tex]E=1500\times 9.8\times 550\\\\E=8085000\ J\\\\or\\\\E=8085\ kJ[/tex]
So, the gravitational potential energy is 8085 kJ.
What is the formula of the compound Pentasilicon trioxide ?
Answer: the molecular formula of trioxide is ClOClO3 or Cl2O4
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Pls pls help me me pls
Answer:
Danger
Explanation:
Suppose you are using distillation to separate cyclohexane and toluene. The boiling point of cyclohexane is ______ oC and the boiling point of toluene is ______ oC. Therefore, the liquid collected first should be ______
Please put an answer in each box.
Answer: The boiling point of cyclohexane is 81oC and the boiling point of toluene is 111oC. Therefore the liquid collected first should be
CYCLOHEXANE
Explanation:
In chemistry, there are various separation techniques that can be used to separate the components of a mixture and even isolate each of these components. A typical example of such separation techniques is DISTILLATION. This is a method of separation that makes use of different boiling points of liquids in a mixture. A mixture of any number of liquids could be separated as long as they boil at different temperatures. Example include:
--> mixture of cyclohexane (boiling point is 81°C) and toluene (boiling point is 111°C)
--> mixture of alcohol (boiling point is 78°C) and water (boiling point 100°C).
The process involves heating the mixture of liquids until the more volatile liquid ( that is the one with the lower boiling point) changes to vapour. The vapour is cooled by passing it through a condenser and collected in a liquid form known as distillate.
Therefore in the mixture of cyclohexane and toluene, the liquid collected FIRST should be CYCLOHEXANE.
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Rank the following compounds in order of decreasing boiling point: sodium chloride (NaCl), methane (CH4), and iodomethane (CH3I). Rank from highest to lowest boiling point.
Answer:
CH4< CH4I< NaCl
Explanation
NaCl has the boiling point of 1,413°C ( 2,575°F )
CH3I has a boiling point of 42°C ( 107°F )
CH4 has the boiling point of -161.6°C ( -258.9°F )
Calculate the individual percent recoveries of benzoic acid, naphthalene and 3-nitroaniline if you were able to collect 9.75 g of benzoic acid, 6.41 g of naphthalene, and 7.71 g of 3-nitroaniline from a set of extractions. The starting mass of the mixture was 26.24 g. (0.6 pt)
Answer:
Benzoic acid= 37.16%
Naphthalene = 24.43%
3-Nitroaniline= 29.38%
Explanation:
Data given:
percentage recovery of benzonic acid = 9.75/26.24 * 100 = 37.16%
Percentage recovery of napthalene = 6.41/26.24 * 100 = 24.43%
Percentage recovery of 3-nitroaniline = 7.71/26.24 * 100 = 29.38%
which straight-chain alkane would you predict to be the most viscous? all are liquids exhbiting the general bonding pattern ch3-(ch2)n-ch3
The question is incomplete, the complete question his;
Which straight chain alkane below would you predict to be the most viscous? Why? All are liquids exhibiting the general bonding pattern CH3-(CH2)n-CH3
C9H20
C10H22
C5H12
C6H14
C12H26
Answer:
C12H26
Explanation:
Generally, the viscosity of a liquid increases with increase in molecular mass of the substance.
Liquids of high molecular mass do not flow easily. This means that they posses high viscosity.
Thus, since C12H26 has the highest molecular mass among the options given in the question, C12H26 exhibits the greatest viscosity.
Suppose a 0.042M aqueous solution of phosphoric acid (H3PO4) is prepared. Calculate the equilibrium molarity of HPO4^−2.
Answer:
2.89x10⁻⁵M = [HPO₄²⁻]
Explanation:
The equilibrium of H3PO4 in water occurs H2PO4-:
H3PO4(aq) + H2O(l) ⇄ H3O⁺(aq) + H2PO4⁻(aq)
pKa = 2.16. And as pKa = -log Ka; Ka = 10^-2.16
Ka = 6.9183x10⁻³ = [H3O⁺] [H2PO4⁻] / [H3PO4]
As both [H3O⁺] and [H2PO4⁻] comes from the same equilibrium,
[H3O⁺]=[H2PO4⁻] :
[H3O⁺] = X
[H2PO4⁻] = X
[H3PO4] = 0.042 - X
Where X is reaction coordinate
Replacing:
6.9183x10⁻³ = [X] [X] / [0.042 - X]
6.9183x10⁻³ = X² / 0.042 - X
2.905686x10⁻⁴ - 6.9183x10⁻³X - X² = 0
Solving for X:
X = -0.02M. False solution. There is no negative concentration.
X = 0.014M. Right solution
[H2PO4⁻] = 0.014M
In the second equilibrium:
H2PO4⁻(aq) + H2O(l) ⇄ HPO4-(aq) + H3O+(aq)
Based on the same principles of the last equilibrium:
pKa2 = 7.21
Ka2 = 6.166x10⁻⁸ = [HPO4-] [H3O+] / [H2PO4⁻]
[HPO4-] = X
[H3O+] = X
[H2PO4⁻] = 0.014M - X
6.166x10⁻⁸ = X² / [0.014M - X]
8.3623x10⁻¹⁰ - 6.166x10⁻⁸X - X² = 0
Solving for X:
X = -0.0000289485. False solution.
X =
2.89x10⁻⁵M = [HPO₄²⁻]If a student drops 2.3g pieces of magnesium into a flask of hydrochloric acid, this reaction occurs: Mg + 2HCl= MgCl2 + H2
How many liters of hydrogen can be produced at a pressure of 2 atm and a temperature of 298 K
Answer:
1.2 L
Explanation:
Step 1: Write the balanced equation
Mg + 2 HCl ⇒ MgCl₂ + H₂
Step 2: Calculate the moles corresponding to 2.3 g of Mg
The molar mass of Mg is 24.31 g/mol.
2.3 g × 1 mol/24.31 g = 0.095 mol
Step 3: Calculate the moles of H₂ produced
0.095 mol Mg × 1 mol H₂/1 mol Mg = 0.095 mol H₂
Step 4: Calculate the volume occupied by the hydrogen
We will use the ideal gas equation.
P × V = n × R × T
V = n × R × T/P
V = 0.095 mol × (0.0821 atm.L/mol.K) × 298 K/2 atm = 1.2 L
9. Which property is not important when selecting a material to use as a light bulb filament?
d
high melting point
high vapor pressure
high ductility
Answer:
high melting point
Explanation:
The filament of a bulb is often heated to very high temperatures as the bulb is in operation.
Many times, electric bulbs may have to be on for a whole day and they may reach temperatures that are outrageously high in the process.
The material of the filament must have a very high melting point so that it doesn't melt while the bulb is still in operation.
Answer:
Actually the answer is High Vapor pressure
Explanation:
If 0.250 L of a 5.90 M HNO₃ solution is diluted to 2.00 L, what is the molarity of the new solution?
Answer:
0.74 M
Explanation:
From the question given above, the following data were obtained:
Molarity of stock solution (M₁) = 5.90 M
Volume of stock solution (V₁) = 0.250 L
Volume of diluted solution (V₂) = 2 L
Molarity of diluted solution (M₂) =?
The molarity of the diluted solution can be obtained by using the dilution formula as illustrated below:
M₁V₁ = M₂V₂
5.90 × 0.250 = M₂ × 2
1.475 = M₂ × 2
Divide both side by 2
M₂ = 1.475 / 2
M₂ = 0.74 M
Thus, the molarity of the diluted solution is 0.74 M
From the dropdowns, identify whether the compound contains ionic bonds, covalent bonds, or both. a) CBr4 [ Select ] b) copper(II) sulfate [ Select ] c) N2O3 [ Select ] d) phosphorous trichloride
Answer:
a) Covalent bonds
b) Covalent and ionic bonds
c) Covalent bonds
d) Covalent bonds
Explanation:
Metals and non-metals form ionic bonds (electrons are transferred), whereas nonmetals and nonmetals form covalent bonds.
Identify whether the compound contains ionic bonds, covalent bonds, or both.
a) CBr₄. C and Br are nonmetals. Thus, they form covalent bonds.
b) copper(II) sulfate. Sulfate contains S and O (nonmetals), which are bonded through covalent bonds. Sulfate is bonded to copper (metal) through an ionic bond.
c) N₂O₃. N and O are nonmetals. Thus, they form covalent bonds.
d) phosphorous trichloride. P and Cl are nonmetals. Thus, they form covalent bonds.
Give your familiarity for following terms
1. roasting 2. smelting 4. zone refining 5. polling
Answer:
The roasting process is a delicate combination of art and science . Roasters are familiar with how the beans look and the smells Well, familiarity with the machine makes things much easier to predict, but the best way is to do many different tests .Well, familiarity with the machine makes things much easier to predict, but the best way is to do many different tests.Smelting is a process of applying heat to ore in order to extract a base metal. It is a form of extractive metallurgy. It is used to extract many metals from their ores, including silver, iron, copper, and other base metals.In zone refining, solutes are segregated at one end of the ingot in order to purify the remainder, or to concentrate the impurities. For example, in the preparation of a transistor or diode semiconductor, an ingot of germanium is first purified by zone refining. In zone refining, solutes are segregated at one end of the ingot in order to purify the remainder, or to concentrate the impurities. ... For example, in the preparation of a transistor or diode semiconductor, an ingot of germanium is first purified by zone refining.Polling is the process where the computer or controlling device waits for an external device to check for its readiness or state, often with low-level hardware. For example, when a printer is connected via a parallel port, the computer waits until the printer has received the next character.Explanation:
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It takes to break an carbon-chlorine single bond. Calculate the maximum wavelength of light for which an carbon-chlorine single bond could be broken b
The question is incomplete, the complete question is;
It takes 338. kJ/mol to break an carbon-chlorine single bond. Cal broken by absorbing a single photon Iculate the maximum wavelength of light for which an carbon-chiorine single bond could be Round your answer to 3 significant digits
Answer:
3.55 × 10^-7 m or 355 nm
Explanation:
Now, the energy of the photon = 338 × 10^3/6.02 × 10^23 = 5.61 × 10^-19 J
Recall that;
E= hc/λ
h= planks constant
c= speed of light
λ = wavelength
λ =hc/E
λ = 6.63 ×10^-34 × 3 × 10^8/5.61 × 10^-19
λ =3.55 × 10^-7 m or 355 nm
When Hg2+ concentration is 6.35x10^-4 M, the observed cell potential at 298K for an electrochemical cell with the following reaction is 1.499V. What is the Cr3+ concentration?
3H^2+ (aq) + 2Cr(s)= 3Hg(l) + 2Cr^3+(aq)
Answer:
10.5 × 10^5 M
Explanation:
E°cell = E°cathode - E°anode
E°cell = 0.85 - (-0.74) = 1.59 V
From Nernst's equation;
Ecell = E°cell - 0.0592/n log Q
1.499 = 1.59 - 0.0592/6 log [Cr^3+]/6.35x10^-4
1.499 - 1.59 = - 0.0592/6 log [Cr^3+]/6.35x10^-4
-0.091 = -0.00987 log [Cr^3+]/6.35x10^-4
-0.091/ -0.00987 = log [Cr^3+]/6.35x10^-4
9.22 = log [Cr^3+]/6.35x10^-4
Antilog (9.22) = [Cr^3+]/6.35x10^-4
1.66 × 10^9 = [Cr^3+]/6.35x10^-4
[Cr^3+] = 1.66 × 10^9 × 6.35x10^-4
[Cr^3+] = 10.5 × 10^5 M
What quantity of sodium azide in grams is required to fill a 56.0 liters air bag with nitrogen gas at 1.00 atm and exactly 0 °C:
2 NaN3 is) 2Na (s) + 3N2 (8)
Answer:
108.6 g
Explanation:
2NaN₃(s) → 2Na(s) + 3N₂(g)First we use the PV=nRT formula to calculate the number of nitrogen moles:
P = 1.00 atmV = 56.0 Ln = ?R = 0.082 atm·L·mol⁻¹·K⁻¹T = 0 °C ⇒ 0 + 273.2 = 273.2 KInputting the data:
1.00 atm * 56.0 L = n * 0.082 atm·L·mol⁻¹·K⁻¹ * 273.2 Kn = 2.5 molThen we convert 2.5 moles of N₂ into moles of NaN₃, using the stoichiometric coefficients of the balanced reaction:
2.5 mol N₂ * [tex]\frac{2molNaN_3}{3molN_2}[/tex] = 1.67 mol NaN₃Finally we convert 1.67 moles of NaN₃ into grams, using its molar mass:
1.67 mol * 65 g/mol = 108.6 gA compound has a formula mass of 228.0 and an empirical formula of C2H4O3. What is the molecular formula
Answer:
C₆H₁₈O₉
Explanation:
First we calculate the molar mass of the compound represented by the empirical formula:
Molar Mass = (Molar mass of C) * 2 + (Molar Mass of H) * 4 + (Molar Mass of O) * 3Molar Mass = 12 * 2 + 1 * 4 + 16 * 3 = 76 g/molThen we divide the given formula mass by the calculated molar mass:
228 / 76 = 3Thus we multiply by 3 the subscripts in the empirical formula:
The molecular formula is C₆H₁₈O₉PLEASE HELP!!!!
Which of the following lists describes characteristics of an acid? (3 points)
Bitter taste, high pH, and caustic
Sour taste, low pH, and dissolves metals
Sour taste, high pH, and dissolves metals
Slippery, low pH, and caustic
Acids have sour taste, low pH and dissolves metals.
The list that describes the characteristics of an acid is that it has sour taste, low pH, and dissolves metals.
Characteristics of an acidAn acid is a chemical substance that has the ability to donate hydrogen ions when involved in a chemical reaction.
The following are the characteristics or features of an acid:
They have a sour taste when tasted.When measured using a pH scale it is less than 7(low pH).They react with active metals to yield hydrogen gas.Therefore, the list that describes the characteristics of an acid is that it has sour taste, low pH, and dissolves metals.
Learn more about acids here:
https://brainly.com/question/1302816
The pKa of an acid can be determined through _____ (reduction, titration, filtration) with a strong base.
Gradually increase the volume of the base, stopping _____ (before, as, after) the equivalence point is reached.
The pKa of the acid is equal to the pH at the _____ (equivalence point, midway volume to the equivalence point, maximum volume).
Answer:
The pKa of an acid can be determined through titration with a strong base.
Gradually increase the volume of the base, stopping before the equivalence point is reached.
The pKa of the acid is equal to the pH at the midway volume to the equivalence point.
Explanation:
An acid HA dissociates in water as follows:
HA ⇄ H⁺ + A⁻ Ka
So, it produces hydrogen ions (H⁺) and a conjugate base (A⁻). The concentrations of HA, H⁺ and A⁻ at equilibrium determine the constant Ka. The pKa is calculated as:
pKa = -log Ka
The relationship between the pH of the solution and the pKa of the acid is described by the Henderson-Hasselbalch equation:
pH = pKa + log ([A⁻]/[HA])
The pKa can be experimentally determined by acid-base titration, in which a strong base is added to the acid solution. As the base is added, the acid HA is neutralized and the conjugate base A⁻ is formed. Thus, the concentration of the acid ([HA]) increases and the concentration of the conjugate base ([A⁻] decreases. The equivalence point is reached when the total amount of acid is neutralized with the added base. Before reaching the equivalence point, at the halfway point, half of the acid is neutralized and converted into the conjugate base. Thus:
[A-] = [HA] ⇒ log [A-]/[HA] = log 1 = 0 ⇒ pH = pKa
We measure the pH at that point and it is equal to the pKa of the acid.
Which statement is true about molarity and percent by mass? (3 points)
They have the same unit.
They are inversely related.
They are different units of dilution.
They are different units of concentration.
Answer:
The guy above used photoshop here is the actual answer.
Explanation:
The true statements about molarity and percent by mass is that they are the different units of concentration
What is concentration?Concentration of any substance present in any solution guves idea about their relative amount in that and it can de described in terms of molarity and percent by mass.
Molarity is define as the moles of solute present in per unit volume of the solution and has a unit of mol/L.Percent by mass is define as the mass of solute present in total mass of solution and it is a unit less quantity.They both gives idea about the concentration, not of the dillutions.They are not inversely related else they are directly related to each other as they are depends on the moles or mass of solute.Hence, molarity and percent by mass are the different units of concentration and directly related to each other.
To know more about molarity & percent mass, visit the below link:
https://brainly.com/question/26150306
What differences does distillation rely on to separate out parts of a solution?
O A. Different densities
O B. Different molecular masses
C. Different boiling points
O D. Different molecular sizes
Different boiling point.
Because in distillation the substance with lower boiling point is evaporated, leaving the other material(s).
Distillation relies on different boiling points to separate out parts of a solution.
Amateur radio operators in the United States can transmit on several bands. One of those bands consists of radio waves with a wavelength near 160m. Calculate the frequency of these radio waves on the freauensy of these radio waves.
Answer:
1.875 × 10^6 Hz
Explanation:
From the wave formula;
V= λf
λ= wavelength of the radio waves
f= frequency of the radio waves
f= v/λ
Since radio waves is an electromagnetic wave, it possesses the speed of light which is 3 × 10^8 m/s
f= 3 × 10^8 m/s/160 m
f= 1.875 × 10^6 Hz
Suppose that you move from a Suppose that you move from a town near the ocean to a town in the mountains. To what atmospheric changes would your body need to adjust? town near the ocean to a town in the mountains. To what atmospheric changes would your body need to adjust?
Answer:
all I can say is town near the ocean atmospheric changes will be cooler, warm, sea breeze, and fresh healthy air. Then when it comes to the mountain lot of change firstly there's a dry air
What is determined by calculating the slope of the position versus time graph distance
Answer:
Determining the Slope on a p-t Graph. It was learned earlier in Lesson 3 that the slope of the line on a position versus time graph is equal to the velocity of the object. ... If the object has a velocity of 0 m/s, then the slope of the line will be 0 m/s. The slope of the line on a position versus time graph tells it all.
Explanation:
#carryonlearning
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Question 2
1 pts
How many moles of carbon tetrachloride are present in
18.Og of CC14?
i think .117018
now to get to the 20charaeactrs minimum.
What is the phase change from solid to gas?
O A. Condensation
O B. Sublimation
O C. Freezing
O D. Vaporization
Answer:
The answer is B, sublimation.
Answer:
The correct answer
B . Sublimation
What is the cell potential of an electrochemical cell that has the half-reactions shown below?
Ag⁺ + e⁻ → Ag
Fe → Fe³⁺ + 3e⁻
Answer:
E°(Ag⁺/Fe°) = 0.836 volt
Explanation:
3Ag⁺ + 3e⁻ => Ag°; E° = +0.800 volt
Fe° => Fe⁺³ + 3e⁻ ; E° = -0.036 volt
_________________________________
Fe°(s) + 3Ag⁺(aq) => Fe⁺³(aq) + 3Ag°(s) ...
E°(Ag⁺/Fe°) = E°(Ag⁺) - E°(Fe°) = 0.800v - ( -0.036v) = 0.836 volt
