Buffer #1: 0.15 M HF(aq) and 0.10 M NaF(aq) Buffer #2: 0.090 M HF(aq) and 0.060 M NaF(aq). The pH values of Buffers #1 and #2 are equal, and the buffering capacity of Buffer #1 is higher than that of Buffer #2.
A buffer is a solution that is capable of withstanding changes in pH caused by the introduction of acid or base substances. It may neutralize tiny quantities of additional acid or base, allowing the pH of the solution to remain reasonably constant.
For buffer 1;
[HF] = 0.15 M [NaF] = 0.10 MUnder Standard Conditions, Ka(acid dissociation constant) for HF = 3.5 × 10⁻⁴
pKa = -log Ka
pKa = -log (3.5 × 10⁻⁴)
pKa = 3.454
The formula for calculating the buffer value can be represented by:
[tex]\mathbf{pH = pKa + log \dfrac{([A^+])}{([HA])}}[/tex]
[tex]\mathbf{pH = 3.454 + log \Big(\dfrac{0.10}{0.15}}\Big)[/tex]
pH = 3.2779
For Buffer 2;
[HF] = 0.090 M [NaF] = 0.060 M[tex]\mathbf{pH = 3.454 + log \Big(\dfrac{0.06}{0.09}}\Big)[/tex]
pH = 3.2779
We can see that the pH of buffer 1 is equivalent to the pH of buffer 2.
Buffer capacity measures a solution's capacity to endure pH fluctuations by either accepting or detaching H+ and OH- ions.
For Buffer 1:
The buffer capacity can be expressed by using the formula:
[tex]\mathbf{\beta = \dfrac{2.3 \ Ka [H^+] [C]}{(Ka+ [HA])^2}}[/tex]
where;
C = total concentration of buffer components i.e. [HA] + [A⁻][tex]\mathbf{\beta = \dfrac{2.3 \ \times 3.5 \times 10^{-4} \times (0.15) (0.15 \times 2)}{(3.5 \times 10^{-4} + (0.15)^2 }}[/tex]
[tex]\mathbf{\beta = \dfrac{3.6225 \times 10^{-5}}{0.02260}}[/tex]
[tex]\mathbf{\beta = 0.0016}[/tex]
For Buffer 2:
[tex]\mathbf{\beta = \dfrac{2.3 \ \times 3.5 \times 10^{-4} \times (0.09) (0.09 \times 2)}{(3.5 \times 10^{-4} + (0.09)^2 }}[/tex]
[tex]\mathbf{\beta = \dfrac{1.3041 \times 10^{-5}}{0.008163}}[/tex]
[tex]\mathbf{\beta = 0.00159}[/tex]
Therefore, we can conclude that the pH values of Buffers #1 and #2 are equal, and the buffering capacity of Buffer #1 is higher than that of Buffer #2.
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distingush between conduction, convection, and radiation.
Answer:
Conduction is between solids, convention is between liquid and radiation between the sun and a body on the earth
Answer:
In conduction, heat transfer takes place between objects by direct contact. In convection, the heat transfer takes within the fluid. In radiation, heat transfer occurs through electromagnetic waves without involving particles. ... The heat transfer occurs through a heated solid object.
Explanation:
The worldwide record of earthquake activity indicates that _____.
a. the frequency of activity is stable (constant)
b. the frequency of activity is diminishing
c. the frequency of activity is slowly increasing
d. the frequency of activity is increasing rapidly
Answer:
My answer is d. hope this'll help
What is the name of this compound?
Answer:
hexagon
Explanation:
Answer:
um how is this a question? is there no info on how many protons neutrons electrons and what elements are in the compound. how do you find out a compound if you don't know what the elements in it are
What is polyethylene?
A.Thermoplastic polymer
B.Electroplastic polymer
C.Thermoplastic monomer
D.Single monomer
Explanation:
thermoplastic polymer
Please help me out I have 20 mins, show work !
Answer:
8)Dinitrogen tetraoxide
9)+5
10)NH4HSO4
Explanation:
please mark me as brainlest
Beautiful vases, figurines, and plate are some of the households which are useful. These objects are produced from a special kind of mixture. What kind of mixture do they possess?
Solution
Suspension
Colloid
Particles
Beautiful vases, figurines, and plate are a kind of mixture called colloid.
A colloid comprises of the dispersion of one substance in another. Therefore in a colloid there must be;
The dispersed substanceThe dispersing mediumThese beautiful vases, figurines, and plate are made of ceramics. In ceramics, composite materials and fibers are dispersed in a polymer matrix. Hence these beautiful vases, figurines, and plate are made of colloids.
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why copper and chromium having Anamalous electronic configuration?
Answer:There are two main exceptions to electron configuration: chromium and copper. See below
Explanation:
These two elements are exceptions because it is easier for them to remove a 4s electron and bring it to the 3d subshell, which will give them a half filled or completely filled subshell, creating more stability.
How many mass would be contained in 0.01mol of NaOH
Answer:
Explanation:
1mol NaOH---->40
0.01mol NaOH------>x
X=40×0.01=0.4
18.Which shows chemical weathering?
A. Rocks are dissolved by acid.
B. Rocks are irregularly shaped.
C. Rocks are broken into pieces.
D. Rocks are changed into finer particles.
19. How long does it take for the moon to rotate on its axis?
A. 12 days
B. 20 days
C. 15 days
D. 28 days
20.Why is the moon important to human beings?
A. It help farmer know the right time to plant crops.
B. It makes planet earth beautiful.
C. It makes the earth climates bearable.
D. It makes earth a more livable planet and stay in its axis.
22.Which statement is NOT true?
A. Stars differ in size.
B. Red stars are the hottest star.
C. The sun is a medium sized yellow star.
D. Supernovas are exploding stars.
24.What is the effect of the northeast monsoon in the country?
A. Brings rainfall.
B. Cold weather and little rainfall.
C. No rainfall and cold weather.
D. Little rainfall and warm weather.
Explanation:
18 A
19 C
20 C
22 A
24 B
hope this helps you.
A cylinder was found in a storeroom of a manufacturing plant. The label on the cylinder was gone, and
no one remembered what the cylinder held. A 0.00500-gram sample was found to occupy 4.13 mL at 23°C
and 745 torr. The sample was also found to be composed of only carbon and hydrogen. Identify the gas
The gas that is to be identified in the problem is C2H2
From the ideal gas equation;
PV = nRT
P = pressure of the gas = 745 torr or 0.98 atm
V = volume of the gas = 4.13 mL or 0.00413 L
n = number of moles of the gas = ?
R = gas constant = 0.082 atm Lmol-1K-1
T = temperature of the gas = 23°C + 273 = 296 K
n = PV/RT
n = 0.98 atm × 0.00413 L/0.082 atm Lmol-1K-1 × 296 K
n = 0.00405/24.272
n = 0.000167 moles
Recall that;
Number of moles = mass/molar mass
molar mass = mass/Number of moles
molar mass = 0.00500-gram/0.000167 moles
molar mass = 30 g/mol
Since it is a hydrocarbon;
[12 +1]n = 30
n = 30/13
n = 2
The gas is C2H2
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Cho a g hhA (Na và Ca) vào y g H2O thì thu đc 6,72l khí (đktc) và ddB trg đó nồng độ M kiềm canxi. Tính x,y bt C% của Na là 8%
Answer:
t5gbt 4 tbg3rvb tjj5tb4b4bv
Explanation:fhtb v4bvtvhbvv bh
Do you think more foam will form if the ice cream is added to the glass before the root beer or after the root beer? Explain.
Answer:This is a very interesting question. I think of it like this. You have a piece off ice floating in the water. Let's say a portion off. It is submerged. No. If this the portion off the sub marched portion has a volume be, it means that the buoyant force will be times the density off water times G. Now this will be equal to the point force, which is equal to the weight off the ice block. Now, once I this ice turns into water, it will still have the same rate. But now its density will be equal to that of water. So it's wait will be saying mass times G. Now you can cancel T on mass is equal to three times rope. Now, this week is this volume and if you notice, row is also the density of water, which means this mass of water contains will help this volume. It means once the ice becomes water, it perfectly fits into this volume, which means the water level's stays exactly the same. It's almost magical, but what happens if there isn't a butt in a bubble? You can think off it in a slightly mathematical way, If you have an air bubble in on Ice Cube, it's total density. Its average density will be less than the density off ice, but an easier way to think about it is like this. You have a piece off ice, which has in a bubble in it on dhe, obviously that it's water here and now. Once the ice melt, the amount of water displaced will be. The volume of the water displaced will equal the weight off the ice. So the what? The water in the ice, if it's exactly in this volume, so it must still be the same. But the answer will be different if you have a great off sandal. If you have a grain of sand, let's say somewhere over here the total density off the ice cube will be larger. The average density on once the ice melt the sand simply false down, which means this ice this piece off ice was further down than it for the lower in the water than it would have been if it was simply made off ice. So to make up for that, when the ice melts, the amount off the volume off the water will be less than the amount of water displaced, so the level of water will decrease if it were if there were a grain of sand in the ice, so you would expect that the water level would tries if, uh, in the case off the air bubble. But it's the identity of baby. It is so small that it simply doesn't count.
Explanation:
when you leave orange juice in the fridge for a while, the pope begins to sync to the bottom of the container. Why does this happen?
Orange Juice is a heterogeneous mixture. This means the orange juice contains more than one component.
This is true because orange juice contains two components. They are:
The juiceThe pulpThe reason why the pulp in orange juice sinks to the bottom is because the pulp is denser than the juice. So it is heavier and sinks to the bottom.
Density is how dense or heavy a substance is. Orange juice is a mixture of pulp and juice. When you leave orange juice in the fridge for a while, the pulp begins to sync and settle at the bottom and this is because the pulp is heavier or denser than the orange juice. So the heavier component which is the pulp sinks to the bottom.To learn more, visit the link:
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Draw an energy diagram showing the process involved in the production of an absorption spectrum. Use this diagram to help you construct a step-by-step written description of what is happening at the atomic level. Make sure to label the axis, energy levels, and cause of the electron transition.
At the atomic level, electrons absorb a particular wavelength of energy and move from a lower to a higher energy level.
In the absorption spectrum, energy is absorbed causing a specie to move from a lower to a higher energy level. This is shown in the diagram attached to this answer.
At the atomic level, electrons absorb a particular wavelength of energy and move from a lower to a higher energy level.
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A video camera would be most beneficial to someone who investigates?
Answer:
a person or persons murder
Answer: the aerodynamics of hummingbird wings.
Explanation: i got it right
What is the molarity of a solution that contains 114.4g NaCl (molar mass= 58.44 g/mol) in 1.2 L solution?
Answer:
1.6 M.
Explanation:
We want to find the molarity of a solution that contains 114.4 g NaCl in a 1.2 L solution.
Recall that molarity is given by:
[tex]\displaystyle \text{M} = \frac{\text{ mols solute}}{\text{ L soln.}}[/tex]
Convert 114.4 g NaCl to mol NaCl using its molecular weight:
[tex]\displaystyle 114.4 \text{ g NaCl} \cdot \frac{1 \text{ mol NaCl}}{58.44 \text{ g NaCl}} = 1.958\text{ mol NaCl}[/tex]
Therefore, the molarity of the solution will be:
[tex]\displaystyle \text{M} = \frac{1.958 \text{ mol NaCl}}{1.2\text{ L soln.}} = 1.6 \text{ M}[/tex]
In conclusion, the molarity of the solution is 1.6 M.
Himalayan pink salt has a density of 1.03 g/mL.
Calculate the volume, in liters (L), per kg of that salt.
The volume, in liters, per kg of the Himalayan pink salt would be 0.97 L
Recall that: density = mass/volume
Hence: volume = mass/density
In this case, the density of the Himalayan pink salt is 1.03 while the mass we are working with is 1 kg.
1 kg is equivalent to 1000 g
Thus: volume = 1000/1.03
= 970.87 mL
Divide by 1000 to convert to L
970.87/1000 = 0.97 L
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How many different types of elements make up one molecule of potassium perbromate, KBrO4?
Answer:
3.
Explanation:
potassium
bromine
oxygen
Thủy phân hoàn toàn 62,5 g dd saccarozo 17,1%, trong môi trường axit
vừa đủ ta thu được dung dịch X. Cho AgNO,NH, vào dd X và đua nhẹ thu
được khối lượng Ag là
Answer:
có trong vietjack nè má, vô coi đi
Explanation:
https://khoahoc.vietjack.com/question/7374/thuy-phan-hoan-toan-62-5-gam-dung-dich-saccarozo-17-1-trongmoi-truong-axit
What is made when certain wavelengths of light, or colors, are given off by hot gases and can be thought of like a fingerprint for elements?
constellations
nebulae
supernovas
emission lines
The emission lines of an element is characteristics of the element and can be thought of like a fingerprint for elements. Emission spectra is used to identify the elements.
What is emission spectrum ?The electromagnetic radiation spectrum produced when an electron changes from a high energy state to a lower energy state is known as the emission spectrum of a chemical element or chemical compound.
The energy difference between the two states is equal to the photon energy of the emitted photon. Each atom contains a large number of potential electron transitions, and each transition has a distinct energy difference.
An emission spectrum is made up of a variety of transitions that result in various radiated wavelengths. The emission spectra of each element is distinct. Therefore, option d is correct.
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1) Is a moth bursting out of cocoon a chemical or physical change? (I put chemistry because i didn't know what else to put) 2) Is playing with purple and green slime chemical or physical change
Answer:
1)A moth bursting out of a cocoon is neither a chemical or physical change, it's a biological change. If I had to chose it would be a physical change though. Not to sure...
2)Playing with slime is a physical change.
Explanation:
1)The reason why I would chose physical change is because the moth is changing it's physical state more than it's chemical composition, but you should say both if that's an option.
2)A physical change is when the temperature, shape, or state of matter changes. A chemical change occurs when the actual substance changes. An example of this is a chemical reaction. Because the slime is changing shape and not substances, I would say that it's obviously a physical change.
Hope this helps, sorry that I'm not too sure about the 1st question.
Who is the intended audience?
Answer:
From Middle school to college
Explain the difference between accuracy and precision.
Answer:
Accuracy is the degree of closeness to true value.
Precision is the degree to which an instrument or process will repeat the same value.
Hope it helps....
Answer:
Accuracy and precision are alike only in the fact that they both refer to the quality of measurement, but they are very different indicators of measurement. Accuracy is the degree of closeness to true value. Precision is the degree to which an instrument or process will repeat the same value
How are physical changes related to state of matter changes?
Answer:
Changes of state are physical changes. They occur when matter absorbs or loses energy. Processes in which matter changes between liquid and solid states are freezing and melting. Processes in which matter changes between liquid and gaseous states are vaporization, evaporation, and condensation.
hope this helped
The amount of K O H needed, in grams, in reaction 1 if you want to have 10% excess K O H
The mass of KOH reacted is 2.576 g. To have a 10% excess KOH, i need 2.833 g of KOH.
The equation of the reaction is;
2 Al(s) + 2 KOH(aq) + 6H20 (l) --------> 2K+ (aq) + 2 Al(OH)4^- (aq) + 3H2(g)
We are told that 1.25 g of Al was used in the reaction, hence;
Number of moles of Al = 1.25 g/27 g/mol = 0.046 moles
To obtain the amount of KOH required for the reaction;
2 moles of Al reacts with 2 moles of KOH
0.046 moles of Al also reacts with 0.046 moles of KOH
Mass of KOH reacted = 0.046 moles of KOH × 56 g/mol = 2.576 g
To have a 10% excess KOH;
Let the needed mass of KOH be x
x =2.576 g + (0.1 × 2.576 g)
x = 2.833 g
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Assuming you start with 1.25 g of pure aluminum, calculate the following:
1) The amount of potassium hydroxide, KOH, in grams, needed to react with all of the 1.25 g of Al. The reaction is: 2 Al(s) + 2 KOH(aq) + 6H20 (1) ---> 2K+ (aq) + 2 Al(OH)4^- (aq) + 3H2(g) 2) The amount of KOH needed, in grams, in reaction 1 if you want to have 10% excess KOH.Calculate the molarity of each of the following solutions.
1.30 mol of KNO3 in 250.0 mL of solution
0.500 mol of BaCl2 in 100.0 mL of solution
0.195 mol of Na2CO3 in 200.0 mL of solution
7.00 mol of C6H12O6 in 250.0 mL of solution
Answer:
5.2M, 5M, 0.975M, 28M
Explanation:
M = ( moles × 1000 ) ÷ volume
Molarity is affected by temperature. Its unit is mole/litre. It measure the concentration of any solute in a solution. Thus the molarity of [tex]KNO_{3}[/tex],[tex]BaCl_{2}[/tex],[tex]Na_{2}CO_{3}[/tex] and[tex]C_{6}H_{12}O_{6}[/tex] are 5.2mol/litre, 5mol/litre, 0.97mol/litre, 28mol/litre respectively.
What is molarity?
Molarity can be calculated by dividing number of moles of solute by volume of solution in liter.
Other concentration terms are molality, normality and mole fraction. Molarity can be used to find out the ionic strength of any solution
Mathematically,
Molarity= number of moles of solute/volume of solution in litre (1)
1) Molarity of [tex]KNO_{3}[/tex]= {1.30 mol ×(1000ml/l)}÷250.0 mL=5.2mol/litre
2)Molarity of [tex]BaCl_{2}[/tex]= {0.500 mol ×(1000ml/l)}÷100.0 mL=5mol/litre
3)Molarity of[tex]Na_{2}CO_{3}[/tex]= {0.195 mol ×(1000ml/l)}÷200.0 mL=0.97mol/litre
4)Molarity of [tex]C_{6}H_{12}O_{6}[/tex] = {7.00 mol ×(1000ml/l)}÷ 250.0 mL=28mol/litre
Thus the molarity of [tex]KNO_{3}[/tex],[tex]BaCl_{2}[/tex],[tex]Na_{2}CO_{3}[/tex] and[tex]C_{6}H_{12}O_{6}[/tex] are 5.2mol/liter, 5mol/litre, 0.97mol/litre, 28mol/litre respectively.
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Answer:
what the model is describing is the molecules. when molecules are tightly packed they form a solid like ice, and when the ice is melting forms a liquid because the molecules are spreading out. when the ice evaporates (gas) the molecules are moving about and are not touching eachother
What is the energy of a photon with a wavelength of 260nm?
Answer:
4.76
Explanation:
The greater your capacity to love, the greater your capacity to feel the pain.
Answer:
that's true
Explanation:
Answer question based on the periodic table entry for gallium.
How many neutrons does gallium have?
a. 70
b. 39
c. 69
d. 31
Answer:
b. 39 Neutrons would be correct.