The pH of the acid solution after the chemist has added 78.4 mL of the NaOH solution to it is 5.
In this titration, the analytical chemist is determining the pH of an acetic acid solution after adding a known amount of sodium hydroxide (NaOH) solution.
The initial volume of the acetic acid solution is 65.8 mL and its concentration is 0.7600 M, while the concentration of the NaOH solution is 0.3500 M and a volume of 78.4 mL is added.
To calculate the pH of the resulting solution, the chemist needs to first determine the moles of acetic acid and NaOH present in the solution after the addition of the NaOH solution. At the equivalence point, the moles of NaOH added are equal to the moles of acetic acid present in the solution. So, the initial moles of acetic acid can be calculated as follows:
moles of HCH3CO2 = volume of HCH3CO2 x concentration of HCH3CO2
= 65.8 mL x 0.7600 M
= 0.0500 moles
Since the volume of NaOH solution added is 78.4 mL, the moles of NaOH added can be calculated as follows:
moles of NaOH = volume of NaOH x concentration of NaOH
= 78.4 mL x 0.3500 M
= 0.0274 moles
At the equivalence point, the moles of NaOH added will react with all of the moles of acetic acid present, yielding a solution of sodium acetate and water.
This solution will be basic due to the presence of excess hydroxide ions (OH-). The number of moles of sodium acetate formed will be equal to the number of moles of NaOH added, which is 0.0274 moles.
The moles of acetic acid that remain in solution after the addition of the NaOH solution can be calculated by subtracting the moles of NaOH added from the initial moles of acetic acid:
moles of HCH3CO2 remaining = initial moles of HCH3CO2 - moles of NaOH added
= 0.0500 moles - 0.0274 moles
= 0.0226 moles
Using the Henderson-Hasselbalch equation, we can calculate the pH of the solution after the addition of the NaOH solution:
pH = pKa + log([A-]/[HA])
where pKa is the dissociation constant of acetic acid, [A-] is the concentration of the acetate ion, and [HA] is the concentration of the remaining acetic acid.
At the equivalence point, the concentration of the acetate ion is equal to the moles of sodium acetate formed divided by the total volume of the solution:
[A-] = moles of NaC2H3O2 / (initial volume + volume of NaOH added)
= 0.0274 moles / (65.8 mL + 78.4 mL)
= 0.0995 M
The concentration of the remaining acetic acid can be calculated by dividing the remaining moles of acetic acid by the total volume of the solution:
[HA] = moles of HCH3CO2 remaining / (initial volume + volume of NaOH added)
= 0.0226 moles / (65.8 mL + 78.4 mL)
= 0.0819 M
Substituting these values into the Henderson-Hasselbalch equation gives:
pH = 4.70 + log(0.0995/0.0819)
= 5.
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A mining crew extracted two different types of minerals from underground. Then, they transferred the same amount of energy into both minerals. Why did mineral A change while mineral B stayed the same? Explain what happened to the molecules of both minerals
Explanation:
A mining crew extracted two different types of minerals from underground. Then, they transferred the same amount of energy into both minerals. Mineral A changed and mineral B stayed the same phase because mineral B has a stronger molecular attraction than mineral A.
Periodic law states that elements show a
A. repetition of their physical and chemical properties when arranged according to increased atomic number
B. repetition of their physical and chemical properties when arranged according to increased atomic mass
C. repetition of their physical and chemical properties when arranged according to increased atomic size
D. repetition of their physical and chemical properties when arranged according to increased atomic radius
Answer:
A. repetition of their physical and chemical properties when arranged according to increased atomic number
Explanation:
There are various kind of elements that are present in periodic table. Some elements are harmful, some are radioactive, some are noble gases. Therefore, option A is correct option.
What is periodic table?Periodic table is a table in which we find elements with properties like metals, non metals, metalloids and radioactive element arranges in increasing atomic number.
Periodic table help a scientist to know what are the different types of elements are present in periodic table so that they can discover the new elements that are not being discovered yet.
Periodic law states that elements show a repetition of their physical and chemical properties when arranged according to increased atomic number.
Therefore, the correct option is option A out of given options.
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Can someone help me please. chem.
Answer:
linar
Explanation:
what's the answer? please help
Answer:
a usually reversible change in the physical properties of a substance, as size or shape
For example:
Freezing a liquid is a physical change.
Answer:I like bread
I like ya cut G
So that's step by step solution to get to the answer
Particles of a suspension will settle while particles of a colloid do not. Why dose this happen?
Answer:
The dispersed particles are spread evenly throughout the dispersion medium, which can be a solid, liquid, or gas. Because the dispersed particles of a colloid are not as large as those of a suspension, they do not settle out upon standing.
Explanation:
A boat at rest on the ocean moves up and down as water moves past it. What can be concluded about the nature of the water particles in the waves from rl this observation
What is the random movement and mixing of particles?
9 letters in the world the second one is “i” and the 6th “s”
Answer:
diffusion
Explanation:
Diffusion can be defined as the net movement of particles from a high concentration to a low concentration. This sounds like the most plausible word in this case.
Radiant heat is typically found
A.in empty space
B.I’m water
C.in mountains
D.in bricks
Answer:
A.in empty space
Explanation:
Radiant heat creates heath through both convection and radiation. Their purpose is to heat up an environment, aka empty space.
Look at the image below:
Mid ocean ridge
Sea towe
Marie Sedie
Osta 7m
WORM
PC
hohe materieur
Tron
Orope
thenosphere
perduta
What type of plate boundary is shown here?
convergent
divergent
transform
Answer:
Divergent
20 words
Answer:
divergent...........................
Thomson concluded that .......
A- electrons must be parts of the atoms of all elements
B- Electrons are not parts of the atoms of all elements
C-None from the previous
Answer:
A. electrons must be parts of the atoms of all elements
The Sun appears to move across the sky each day. What causes this?
A.the spinning of Earth on its axis
B. the path of the Sun around Earth
C. the production of nuclear energy by the Sun
D. the tilt of Earth on its axis
Answer:
a
Explanation:
as the earth rotate around the sun it appears to be moving across the sky
Answer:
The answer is option A
Explanation:
From Earth, the Sun looks like it moves across the sky in the daytime and appears to disappear at night. This is because the Earth is spinning towards the east. The Earth spins about its axis, an imaginary line that runs through the middle of the Earth between the North and South poles.
Please mark me brainliest
The table below lists the naturally occurring isotopes of element X. Calculate the average atomic mass.
Mass of isotope Relative abundance
15.33 amu 28.60%
17.26 amu 13.30%
18.11 amu 58.10%
A) 17.65 amu
B) 17.11 amu
C) 16.90 amu
D) 17.20 amu
Answer:
D
Explanation:
I think it is D
Convert 6.24 x 10g to standard notation.
Answer:
3.45 x 10^5
Explanation:
What will happen to the temperature
when KCI is added to water?
Answer:
As potassium chloride (KCl) dissolves in water, the ions are hydrated. ... Ion-dipole forces attract the positive (hydrogen) end of the polar water molecules to the negative chloride ions at the surface of the solid, and they attract the negative (oxygen) ends to the positive potassium ions.
The Statue of Liberty changing from Copper to Green is an example of...
Group of answer choices
A: Temperature Change
B: Gas Formation
C: Color Change
D: Precipitate
Answer:
answering this for points! Sorry! but its probably A OR C
Explanation:
The breaking down or wearing away of rock and soil is known as... A. earthquake
B. global shift C. weathering D. deposition
Answer:
the breaking down of rock is known as weathering
14. How many liters would 5 moles of oxygen gas take up?
a.0.22L
b.112
c.27.4L
d.55L
Answer:
a 0.22L
Explanation:
Answer:
A
Explanation:
1 moles of oxygen is 0.044L
How many moles of xenon gas are necessary to exert a 0.64atm pressure in an 8.5L container at 300.0K?
0.026 moles is the right answer.
We have that for the Question "How many moles of xenon gas are necessary to exert a 0.64atm pressure in an 8.5L container at 300.0K?" it can be said that moles of xenon gas is
n=0.22moles
From the question we are told
How many moles of xenon gas are necessary to exert a 0.64atm pressure in an 8.5L container at 300.0K?
Generally the equation for the ideal gas is mathematically given as
[tex]n=\frac{Pv}{RT}\\\\n=\frac{0.64*8.5}{0.08206*300}[/tex]
n=0.22moles
Therefore
How many moles of xenon gas are necessary to exert a 0.64atm pressure in an 8.5L container at 300.0K is
n=0.22moles
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What are the characteristics of electromagnetic waves?
Answer: Electromagnetic waves are transverse in nature as they propagate by varying the electric and magnetic fields such that the two fields are perpendicular to each other.
Accelerated charges are responsible to produce electromagnetic waves.
Explanation:
What is the temperature at 11:59 pm?
If sperm and egg cells have half of the number of chromosomes found in other body cells, how do gametes form?
What happens when a cold drink sits in a hot room? A) It remains coldincorrect answer B) It gets warmerincorrect answer C) It starts boilingincorrect answer D) It starts freezingincorrect answer
Answer:
its B
Explanation:
How many mL of a 1.00 M HCl solution would need to be added to 100 mL of 0.263 M ammonia to produce a buffer with a pH of 10.00. The pKa of ammonia is 9.25.
Answer:
3.97mL of 1.00M HCl must be added
Explanation:
The buffer of ammonia and ammonium ion follows the equation:
pH = pKa + log [NH₃] / [NH₄⁺] (1)
Where pH is the pH we want to obtain: 10.00
pKa is the pKa of the buffer: 9.25
[NH₃] could be taken as moles of ammonia
And NH₄⁺ moles of ammonium ion
When NH₃ reacts with HCl:
NH₃ + HCl → NH₄⁺ + Cl⁻
NH₄⁺ is produced. That means moles of ammonia are Initial moles of ammonia - Moles of HCl added
Moles of HCl added = Moles of ammonium ion
The total moles of the buffer are:
0.100L * (0.263mol / L) = 0.0263moles = [NH₄⁺] + [NH₃] (2)
Rewriting (1):
10.00 = 9.25 + log [NH₃] / [NH₄⁺]
0.75 = log [NH₃] / [NH₄⁺]
Replacing (2) in (1):
0.75 = log 0.0263 - [NH₄⁺] / [NH₄⁺]
5.6234 = 0.0263 - [NH₄⁺] / [NH₄⁺]
5.6234[NH₄⁺] = 0.0263 - [NH₄⁺]
6.6234[NH₄⁺] = 0.0263
[NH₄⁺] = 0.00397 moles = Moles HCl
To obtain these moles we must add:
0.00397 moles HCl * (1L / mol) = 0.00397L =
3.97mL of 1.00M HCl must be added
In your own words, explain Earth's atmosphere.
Answer:
yes
Explanation:
because the atmosphere is the shield of earth
In the reaction 2CO2+ 2H2O -> C2H4 + 3O2 , the mole ratio of water to oxygen is
I'm gonna guess 2:3 because you have two moles of water and three moles of oxygen
how would you describe the forces between the particles of solids??
Answer:
Explanation:
In a solid, the attractive forces keep the particles together tightly enough so that the particles do not move past each other. ... The kinetic energy of the molecule is greater than the attractive force between them, thus they are much farther apart and move freely of each other.
balance Ca(NO3)2 + NaCl ---> NaNO3 + CaCl2
Answer:
Ca(NO3)2 + 2 NaCl = 2 NaNO3 + CaCl2
Explanation:
On the left you have an original balance of Ca - 1, N - 2, O - 6, Na - 1, and Cl - 2, and on the right you have a balance of Ca - 1, N - 1, O - 3, Na - 1, Cl - 2.
Ca - 1 Ca - 1
N - 2 N - 1
O - 6 O - 3
Na - 1 Na - 1
Cl - 1 Cl - 2
In order to balance these, you'll have to make both sides equal. To get the N on the right to be equal to the N on the left, you'll have to multiply NaNO3 by 2, thus making it 2NaNO3. By doing this, you will offset the balance of both Na and O.
Ca - 1 Ca - 1
N - 2 N - 2
O - 6 O - 6
Na - 1 Na - 2
Cl - 1 Cl - 2
To balance the rest of the equation, you'll have to multiply both Na and Cl by 2. This will change NaCl to 2NaCl, making the balance look like this:
Ca - 1 Ca - 1
N - 2 N - 2
O - 6 O - 6
Na - 2 Na - 2
Cl - 2 Cl - 2
You will now be left with your final equation Ca(NO3)2 + 2 NaCl = 2 NaNO3 + CaCl2.
Which statement best compares the melting points of magnesium and sodium?
a
Magnesium has a higher melting point because it contributes one additional electron per atom than sodium in the electron sea.
b
Sodium has a higher melting point because it contributes one fewer electron per atom than magnesium in the electron sea.
c
Sodium has a higher melting point because it contributes two fewer electrons per atom than magnesium in the electron sea.
d
Magnesium has a higher melting point because it contributes two additional electrons per atom than sodium in the electron sea.
A because according to electron sea theory magnesium shares two valence electrons in electron sea while sodium shares one suggesting that magnesium has stronger metallic bond than sodium so breaking metallic bond in magnesium will require more energy as compared to breaking metallic bond in sodium
The melting point of magnesium is higher than the melting point of sodium because it contributes two additional electrons per atom than sodium in the electron sea. Thus option d is correct.
What is melting point?Melting point of a substance is the temperature at which it converts from solid state to liquid state where, the two phases are in equilibrium. Melting point is affected by the bond type, molecular weight, temperature and pressure.
Melting point of elements increases along a period because the atomic size is decreasing along the period and molecular weight is increasing. Thus, the nuclear attractive pull increases resulting in higher energy needed to break the attractive force.
Magnesium is 12th element and sodium is 11th element. Thus magnesium is smaller than sodium and have one more electron than sodium. Thus magnesium have high molecular weight and high nuclear attraction leads to its higher melting point.
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What is the name of this molecule?
O A. 1-methylpentane
O B. 1-pentyne
C. cis-1-pentene
O D. Pentane
Answer:
The name of that molecule should be 1-pentyne
so your answr should be B
Explanation:
Molecules are species made up of atoms. The given molecule in the figure is 1-pentyne. Thus, option B is correct.
What is 1-pentyne?1-Pentyne is a chemical compound with the formula C₅H₈, and an internal alkyne group between the first and the second carbon atom.
The molecules consist of twelve bonds including the bonds between the carbon-carbon, and carbon-hydrogen. There is one triple or the alkyne bond present and five carbon hence the name of the molecule is 1-Pentyne.
Therefore, the molecule is option b. 1-Pentyne.
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Why is sterilising the water rarely used in treating the sewage water?
Answer:
Sterilizing the water rarely used in treating the sewage water is described below in details.
Explanation:
Sterilization is the application of a chemical or physical system to eradicate all microorganisms, concluding comprehensive amounts of bacterial content. Heat treatment is the most relevant approach for the sterilization of waste-water that accommodates large levels of masses. well now sterilizing the water is un-usually practiced in managing the sewage water.