Answer:
pH = 4.89
0.6171g of KOH must be added
Explanation:
Sodium acetate reacts with HCl producing acetic acid as follows:
NaC2H3O2 + HCl → HC2H3O2 + NaCl
That means the moles added of HCl are moles of acetic acid produced and moles of acetate are initial moles - moles of HCl
Moles HCl = Moles acetic acid:
0.204L * (0.452mol / L) = 0.0822 moles acetic acid.
Initial moles sodium acetate:
0.500L * (0.400mol / L) = 0.200 moles
Moles sodium acetate:
0.200 moles - 0.0822 moles = 0.1172 moles sodium acetate
The pH of this buffer (Mixture of a weak acid and its conjugate base) is obtained using H-H equation:
pH = pKa + log [A-] / [HA]
Where pH is pH of the buffer,
pKa is pKa of the buffer (4.74 for acetic acid)
[A-] Moles of sodium acetate -Conjugate base-
And HA moles of acetic acid -Weak acid-
pH = 4.74 + log [0.1172 moles] [0.0822 moles]
pH = 4.89In 0.500L the moles of the buffer are:
0.500L * (0.200moles / 0.704L) = 0.142 moles of buffer
For a pH of 0.15 units more (4.89 + 0.15 = 5.04):
5.04 = 4.74 + log [Acetate] / [Acetic acid]
0.3 = log [Acetate] / [Acetic acid]
1.9953 = [Acetate] / [Acetic acid] (1)
And as:
0.142 = [Acetate] + [Acetic acid] (2)
Replacing (2) in (1):
1.9953 = 0.142 - [Acetic acid] / [Acetic acid]
1.9953 [Acetic acid] = 0.142 - [Acetic acid]
2.9953 [Acetic acid] = 0.142 moles
[Acetic acid] = 0.0474 moles of acetic acid must remain after the addition of KOH.
In the beginning, moles of acetic acid are:
0.0822 moles * (0.500L / 0.704L) = 0.0584 moles.
That means moles added of KOH (Equal to moles of acetic acid that react) are:
0.0584 moles - 0.0474 moles = 0.0110 moles of KOH
In grams (Molar mass KOH = 56.1g/mol):
0.0110 moles KOH * (56.1g/mol) =
0.6171g of KOH must be added1. describe what difference if any there would be between the boiling point of alcohol measured in Houston and in Denver (the mile high city)
Answer:
See explanation
Explanation:
The boiling point of a substance at a location depends mostly on the atmospheric pressure in that location. The lower the atmospheric pressure in a location, the lower the boiling point and vice versa.
Boiling point is defined as the temperature at which the vapor pressure of the liquid becomes equal to the atmospheric pressure.
In Denver (the mile high city), alcohol will boil at a lower temperature(due to its high altitude) than in Houston because pressure decreases with height.
The boiling point of alcohol in Houston and Denver will vary as a result of the difference in atmospheric pressure.
The boiling point of a compound at a particular location depends on the
atmospheric pressure of that location. The lower the atmospheric pressure
of a given place or area, the lower the boiling point and vice versa.
In Denver (the mile high city), alcohol will boil at a lower temperature as a
result of its higher altitude than in Houston because atmospheric pressure
decreases with increase in height and vice versa.
Read more on https://brainly.com/question/19529723
What is the hydroxide concentration of a solution with a poH of 2? Is this solution acidic, basic or neutral?
How is the charge found in an element?
Answer:
Positive charge if there are more protons than electrons. Negative charge if there are more electrons than protons. If there's the same amount of protons and electrons, it's a neutral charge.
Explanation:
All matter is made up of electrons and protons. Electrons have a negative charge, protons have a positive charge. A charge is a type of particle measurement, and it is determined based on the amount of protons or electrons in a certain thing. The charge is which one there are more of, and there’s no charge (neutral) if they’re balanced.
If 12.4 mol of Ne gas occupies 122.8 L, how many mol of Ne would occupy 339.2 L under the same temperature and pressure? Record your answer in scientific notation using 3 significant figures.
Answer:
3.43×10¹ mol
Explanation:
Given data:
Initial number of moles = 12.4 mol
Initial volume = 122.8 L
Final volume = 339.2 L
Final number of moles = ?
Solution:
The number of moles and volume are directly proportional to each other at same temperature and pressure.
Formula:
V₁/n₁ = V₂/n₂
Now we will put the values,
122.8 L/ 12.4 mol = 339.2 L / n₂
n₂ = 339.2 L× 12.4 mol / 122.8 L
n₂ = 4206.08 L.mol /122.8 L
n₂ = 34.3mol
In scientific notation:
3.43×10¹ mol
What is the density of an object with a volume of 3ml and a mass of 18 grams
Answer:
The answer is 6 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question we have
[tex]density = \frac{18}{3} \\ [/tex]
We have the final answer as
6 g/mLHope this helps you
Calculate the pH during the titration of 20.00 mL of 0.1000 M trimethylamine, (CH3)3N(aq), with 0.2000 M HClO4(aq) after 9.48 mL of the acid have been added.
Complete Question
Calculate the pH during the titration of 20.00 mL of 0.1000 M trimethylamine, (CH3)3N(aq), with 0.2000 M HClO4(aq) after 9.48 mL of the acid have been added.Kb of trimethylamine = 6.5 x 10-5.
Answer:
The pH is [tex]pH = 9.84[/tex]
Explanation:
From the question we are told that
The volume of trimethylamine, (CH3)3N(aq) is [tex]V_{t} = 20.00mL[/tex]
The concentration of trimethylamine is [tex]C_t = 0.1000 \ M[/tex]
The volume of HClO4(aq) is [tex]V_{h} = 9.48 mL[/tex]
The concentration of HClO4(aq) is [tex]C_h = 0.200 M[/tex]
The Kb value is [tex]K_b = 6.5 * 10^{-5}[/tex]
Generally the the pOH of this reaction is mathematically represented as
[tex]pOH = pK_b + log [\frac{N_h}{N_b} ][/tex]
Here [tex]N_h[/tex] is the number of moles of acid which is evaluated as
[tex]N_h = C_h * V_h[/tex]
=> [tex]N_h = 0.200 * 9.48[/tex]
=> [tex]N_h = 1.896[/tex]
Here [tex]N_t[/tex] is the number of moles of acid which is evaluated as
[tex]N_t = C_t * V_t[/tex]
=> [tex]N_t = 0.100 * 20[/tex]
=> [tex]N_t = 2[/tex]
So
[tex]pOH = -log(K_b) + log [\frac{N_h}{N_b} ][/tex]
[tex]pOH = -log(6.5*10^{-5}) + log [\frac{1.896}{2} ][/tex]
=> [tex]pOH = 4.1639[/tex]
Generally the pH is mathematically represented as
[tex]pH = 14 - pOH[/tex]
=> [tex]pH = 14 - 4.1639[/tex]
=> [tex]pH = 9.84[/tex]
In addition to hydronium ions which type of ion do acids produce? (Choose all that apply)
A. Anion
B. A negative ion
C. Cation
D.A positive ion
Answer:
B
Explanation:
i just read it na, but i forgot the explanation
Answer:
A. and B.
Explanation:
Anion is negative as well as a negative ion.
(Just took the quiz)
A) Earlier you were told that of all of the 14 solutes you will be studying, the only one that is not appreciably ionized in water is aqueous ammonia. What does this statement imply about the equilibrium point of the reaction involving aqueous ammonia/ammonium hydroxide?B) Use your results and conclusions from part (a) to explain why a complicated name like Aqueous ammonia/ammonium hydroxide is used for this solution?
Answer:
Throughout the overview section following portion, the description and according to particular circumstance is defined.
Explanation:
As per the question,
⇒ [tex]NH_3(aq)+H_2O\leftrightarrow NH_4+(aq)+OH-(aq)[/tex]
A weak basis seems to be NH3. It serves as a base since the aqueous solution or phase is protonated. But NH3 +, just becoming a weak base, is therefore deprotonated into form NH3, and therefore also 90% of ammonia becomes found throughout NH3 state in aqueous solution.⇒ [tex]NH_3+(aq) \leftrightarrow NH_3(aq)+H+(aq)[/tex]
However, it is also available in NH3 form throughout the aqueous solution much of the moment.
What is the ground-state electron configuration for the Mn4 ion and is it paramagnetic or diamagnetic?
Answer:
[Ar]3d4 is the ground-state electron configuration for the Mn4 ion
but i don't know whether it is paramagnetic or daimagnetic
Microwave ovens use microwaves with a wavelength of 0.12 meters. How much energy does this wave have? 2 x 10-20 10 mm FI
Answer:
E = 165.75×10⁻²⁶ J
Explanation:
Given data:
Wavelength = 0.12 m
Energy of wave = ?
Solution:
Formula:
E = h c/λ
c = 3×10⁸ m/s
h = 6.63×10⁻³⁴ Js
Now we will put the values in formula.
E = 6.63×10⁻³⁴ Js × 3×10⁸ m/s / 0.12 m
E = 19.89×10⁻²⁶ J.m / 0.12 m
E = 165.75×10⁻²⁶ J
What mass of 2-naphthol would have to be ingested by each rat in a sample set of rats in order to kill half the population of rats? Assume each rat weighs 230 g. Show your calculations for full credit.
Answer:
303.6 mg
Explanation:
Given that:
The lethal dose [tex]LD_{50}[/tex] = 1320 mg/kg
The weight of the rat = 230 g
The lethal dose is the dose of a substance likely to cause death. SO a lethal dose of 50 will cause the death of 50% of the sample of test animals.
Therefore;
The mass of 2-naphthol that would have been ingested by each rat in a sample set of rats in order to kill half the population of rats will be equal to:
[tex]=\dfrac{LD_{50}}{1000} \times wt \ of \ rat[/tex]
[tex]=\dfrac{1320}{1000}\times 230[/tex]
= 303.6 mg
An isotope of the element fluorine has 9 protons and 10 neutrons. What is the name of this isotope?
fluorine
Answer:
fluorine atom
Explanation:
How many liters of blood does a human body have
Answer:
20000
Explanation:
what is the iupac name of CH3-CH2CH(CH3)CH2-COOH
Answer:
Butanoic acid.
Explanation:
Redox reactions stand for oxidation/reduction reactions. True or false: an oxidation reaction is always paired with a reduction reaction.
Answer:
The answer is: true
Explanation:
In redox reactions, the half-reactions of oxidation and reduction always occur simultaneously in pair.
The oxidation half-reaction involved the lost of electrons from a reduced substance (A) to form a oxidized substance (A⁺):
A ⇒ A⁺ + e-
In contrapossition, during the reduction half-reaction the oxidized substance (B⁺) gains electrons to form the reduced subtance (B):
B⁺ + e- ⇒ B
The overall redox reaction is obtained by the addition of the two half-reactions:
A ⇒ A⁺ + e-
B⁺ + e- ⇒ B
-----------------
A + B⁺⇒ A⁺ + B
The electrons gained by B are provided by A, which lost the same number of electrons. Thus, the oxidation/reduction reactions are paired.
how many moles of Na2SO4 are in 0.140 m aqueous solution that was prepared with 2.30 kg of water?
Answer:
0.322 mols of NaSO4
Explanation:
Molality = Mols of Solute / kg of Solvent
Molality is given as 0.140 m = mols/kg
kg of solution is given as 2.30 kg
Mols of Solute = Molality * kg of Solvent
Mols of Solute = [tex]\frac{0.140 }{ 1 kg } *2.30 kg[/tex]
Mols of Solute = 0.322 mols
The number of mole of Na₂SO₄ required to prepare the solution is 0.322 mole
The Molality of a solution is defined as the mole of solute per Kg of water i.e
Molality = mole / mass (Kg) of water.
With the above formula, we can obtain the mole of Na₂SO₄ in the solution as follow:
Molality of Na₂SO₄ = 0.140 M
Mass of water = 2.30 Kg
Mole of Na₂SO₄ =.?Mole = Molality × mass of water
Mole of Na₂SO₄ = 0.140 × 2.30
Mole of Na₂SO₄ = 0.322 moleTherefore, the mole of Na₂SO₄ in the solution is 0.322 mole
Learn more: https://brainly.com/question/4251997
Which statement is true?
Adding energy can change a liquid to a solid.
Solids have no movement of molecules.
Liquids do not have a set volume.
Gases can be compressed to change their volume.
help, Look at the model below. Explain what is correct and/or incorrect about the model based on scale, proportion, and quantity.
Which of the two forces is greater the force on the firefly or the force on the bus explain your answer please I really need help please
It’s due today please
Answer: The force on the firefly
The unfortunate firefly hitting the bus does not change the velocity of the bus very much. Technically there is a change, but it's so very small and miniscule that it barely registers. To any casual observer not paying very close attention, they don't notice anything at all. So effectively the force on the firefly is a lot greater since the firefly got the worst end of the deal.
So in short, we look at the velocity of each object and see which velocity changed the most. In this case, the firefly's velocity changed from whatever speed it was flying to 0 when it stops flying all together. That's why the force is greater on the bug.
You have a two-liter sample of each of the following gases, all at 25 °C and one atmosphere pressure. Which sample will weigh the most?A) Ammonia.B) Argon.C) Carbon dioxide.D) Nitrogen dioxide.E) Oxygen.
Answer: D) Nitrogen Dioxide
Explanation:
The characteristics of moles allow you to find that the correct answer for which sample weighs more is:
D) Nitrogen Dioxide
The molecular weight of the substance is the weight of one mole of a material, where one mole is Avogadro's number of particles.
In all chemical reactions the relationships are given as a function of moles.
Let's find the molecular weight of each of the substances, we take the atomic weights from the periodic table
Element PA (gr / mol)
H 1
C 12
N 14
O 16
Ar 40
A) Ammonia with NH₃ formula
weight of a mole of molecules
MP = 14 + 3
PM = 17 gr / mol
B) Argon symbol Ar
It is a noble gas and does not react
PM = 40 gr / mol
C) Carbon dioxide formula CO₂
Weight per mole of substance
PM = 12 + 2 16
Pm = 44 gr / mol
D) Nitrogen dioxide formula NO₂
Weight per molecular
MP = 14 + 2 16
PM = 46 gr / mol
E) Oxygen symbol O formula O₂
Molecular weights
PM = 2 16
PPM = 32 gr / mol
It indicates that we have two liters of sample, so the number of moles of each substance is the same, therefore the substance that weighs more is Nitrogen Dioxide (NO₂)
When reviewing the different answer, the correct one is:
D) Nitrogen Dioxide
Learn more here: brainly.com/question/19463913
What is chemical weathering
Explanation:
Chemical weathering is caused by rain water reacting with the mineral grains in rocks to form new minerals (clays) and soluble salts. These reactions occur particularly when the water is slightly acidic.
A river and all of its tributaries make up a(n) _________.
Answer:
A river and its tributaries make up a watershed (aka river system or drainage basin)
Pls mark me as brainliest
Answer:
river system
Explanation:
a river and all its tributaries make up a river system
Compound Y has a distribution coefficient of 4.0 when extracted from water with chloroform, with Y being more soluble in chloroform. How many 10.0 mL chloroform extractions would be required to extract at least 95% of Y from a 50.0 mL aqueous solution of water?
For the extraction of at least 95% of Y in water, 3 extractions are to be performed.
Distribution coefficient can be defined as the ratio of the concentration of solute in an organic solvent to water.
Distribution coefficient = [tex]\rm \dfrac{concentration\;in\;solvent}{concentration\;in\;water}[/tex]
For the first extraction, the concentration in organic solvent = X per 10 mlConcentration in water = 100-X per 50 ml
Distribution coefficient = [tex]\rm \dfrac{\frac{X}{10} }{\frac{100-X}{50} }[/tex]
4 = [tex]\rm \dfrac{\frac{X}{10} }{\frac{100-X}{50} }[/tex]
4 = [tex]\rm \dfrac{50X}{1000-X}[/tex]
4000 - 4X = 50X
X = 74.1 %
Thus, after the first extraction, the amount of Y extracted is 74.1%.
We have to extract at least 95% of Y. Thus, the second extraction is performed.
Remaining y = 100 - 74.1Remaining y = 25.9%
The concentration in organic solvent = X per 10 ml
Concentration in water = 25.9 -X
Distribution coefficient = [tex]\rm \dfrac{\frac{X}{10} }{\frac{25.9-X}{50} }[/tex]
4 = [tex]\rm \dfrac{\frac{X}{10} }{\frac{25.9-X}{50} }[/tex]
4 = [tex]\rm \dfrac{50X}{259-X}[/tex]
1036 - 4X = 50X
X = 19.2%
Thus, after the second extraction the amount of Y extarcted = first extraction + second extraction
The amount of Y extracted = 74.1 + 19.2 %
The amount of Y extracted = 93.3%
To reach at least 95% extraction, the third extraction has to be performed.The remaining Y for third extraction = 100 - 93.3
The remaining Y for the third extraction = 6.7%
Concentration in water = 100 - 6.7
Distribution coefficient = [tex]\rm \dfrac{\frac{X}{10} }{\frac{6.7-X}{50} }[/tex]
4 = [tex]\rm \dfrac{\frac{X}{10} }{\frac{6.7-X}{50} }[/tex]
4 = [tex]\rm \dfrac{50X}{67-X}[/tex]
268 - 4X = 50X
X = 5.0%
The total extraction after third extraction = 93.3 + 5%
The total extraction after third extraction = 98.3%.
Thus for the extraction of at least 95% of Y in water, 3 extractions are to be performed.
For more information about the distribution coefficient, refer to the link:
https://brainly.com/question/13599982
Which two types of energy are formed by the transformation shown in the
photo?
A. Chemical energy
thermal energy
B. Thermal energy -
electrical energy
C. Thermal energy -
chemical energy
D. Chemical energy
-
electromagnetic energy
PREVIOUS
Explanation:
i cant even see any thing
Answer: A and D
Explanation:
Is iron man made or natural
Answer:
Iron is natural. Paper is man-made
Explanation:
Answer:
iron
Explanation:
What effect does a high carbon level have on the deep ocean? Why might it be important to keep an eye on the deep ocean carbon levels? What could that one number tell you about the cycle as a whole?
High concentrations of carbon dioxide make it harder for marine animals to respire (to extract oxygen from seawater). This, in turn, makes it harder for these animals to find food, avoid predators, and reproduce. Low concentrations of oxygen can have similar effect
Becay the Ocean's Carbon Balance. The idea seemed simple enough: the more carbon dioxide that people pumped into the atmosphere by burning fossil fuels, the more the oceans would absorb. ... Water trapped at the surface would become saturated, at which point, the ocean would slow its carbon uptake.
What is the acceleration of a car moving at the same speed and in the same direction?
Answer:
if it ain't changing direction the acceleration isn't being affected
For a particular reaction, the change in enthalpy is â9kJmole and the activation energy is 13kJmole. The enthalpy change (ÎH) and activation energy (Ea) for the catalyzed reaction could be which of the following? a. â9kJmole,5kJmole. b. â9kJmole,19kJmole.c. â14kJmole,5kJmole.d. â14kJmole,â13kJmole.
Answer:
The answer is Option a, that is "−9kJmole,5kJmole".
Explanation:
Please find the complete question in the attached file.
In the question, it uses the catalyst inside a process, which does not modify the process eigenvalues, however, it decreases the active energy with an enthalpy of -9kJmole, and also the power for activating decreases around 13 to 5 kJ mole, that's why the choice a is correct.
Does MgO have a structure like that of NaCl or ZnS? If the density of MgO is 3.58g/cm3, estimate the radius (in centimeters) of the O2â anions and of the Mg2+ cations.
Answer:
The radius of O^2- is 1.5*10^-8 cm and the radius of
Mg ^2+ is 6.2*10^-9 cm
Explanation:
Face centered cubic : 1/8 atoms on each edges + 1/2 atoms on each face
= [tex]\frac{1}{8}* 8 + \frac{1}{2}*6[/tex] = 4 effective atoms
MgO have a structure like NaCl forms a lattice of FCC.
density of the lattice = [tex]\frac{ z.M}{a^3*Na}[/tex]
z : no of atoms
M: mass of the atoms
a: radius of the atom
Na: Avogadro's number
a^3(radius) = [tex]\frac{ 4*40.3}{3.58*6.022*10^23}[/tex]
a^3 = 7.477 * 10^-23 cm^3
a = 4.21 * 10^-8 cm
Now calculating the anionic(ra O^2-) and cationic (rc Mg^2+)
in Fcc a = 2[tex]\sqrt{2} ra[/tex]
ra = 1.5*10^-8 cm
a = 2ra + 2rc
rc = a/2 -ra
rc = 6.2*10^-9 cm
The radius of O^2- is 1.5*10^-8 cm and the radius of Mg ^2+ is 6.2*10^-9 cm
A solution of acetic acid is prepared in water by adding 11.1 g of sodium acetate to a volumetric flask and bringing the volume to 1.0 L with water. The final pH is measured to be 5.25. What are the concentrations of acetate and acetic acid in solution? (Assume that the temperature of the solution is 25 degrees Celsius)
Answer:
Molarity acetate: 0.1353M
Molarity acetic acid: 0.0418M
Explanation:
When in solution you have a weak acid (Acetic acid) and its conjugate base (sodium acetate) a buffer is produced. The pH of this buffer is obtained using the H-H equation:
pH = pKa + log [A⁻] / [HA]
Where pH is pH of the solution = 5.25
pKa is pKa of acetic buffer = 4.74
[A⁻] is molarity of acetate ion - Molar mass sodium acetate: 82.03g/mol-:
11.1g * (1mol / 82.03g) = 0.1353moles A⁻ / 1.0L = 0.1353M
And [HA] are moles of acetic acid.
Solving for HA:
5.25 = 4.74 + log [0.1353] / [HA]
0.51 = log [0.1353] / [HA]
3.236 = [0.1353] / [HA]
[HA] = 0.1353M / 3.236
[HA] = 0.0418M