Answer:
The correct answer is 7.8 percent.
Explanation:
As mentioned in the given question, the absorbance (A) of the sample solution is 1.07. To find the concentration of aspirin, Beer's law is used, that is, A = ebc
Here, e is the extinction coefficient, which is equal to 139.322 M^-1cm^-1 as per the standard value for salicylic acid, b is the pathlength, which is equivalent to 1 cm. Now putting the values we get,
A = ebc
c = A / (eb)
c = 1.07 / (139.322 × 1)
c = 0.00768 M
Now to determine the percent salicylic acid in the sample, there is a need to compare the value of concentration determined with the concentration of aspirin given initially.
0.02 grams is the initial concentration of aspirin mentioned in the question. The molar mass of aspirin is 240 g/mol.
Therefore, the moles of aspirin will be,
0.02 / 240 = 8.33 × 10^-5 moles
The final volume of the diluted solution given is 10 ml or 0.01 liters.
The molarity of aspirin in the diluted solution will be,
c1 = 8.33 × 10^-5 / 0.01 = 8.33 × 10^-3 M or 0.00833 M
Now, the percent of salicylic acid in the product will be,
c1 - c / c1 × 100
(0.00833 - 0.00768) / 0.00833 × 100 = 7.8 %
Absorbance is directly proportional to the concentration of the solution. The absorbance can be calculated if the molar absorptivity, path length, and concentration of the absorbing species are known.
The percent of salicylic acid in the solution is 7.8%
Given that:
Absorbance of the solution is = 1.07
Path length = 1 cm.
Applying Beer's Law,
A = ε b c
where,
c = concentration, A = absorbance, ε = constant, and b = path length
Now, putting the values in above equation
c = [tex]\dfrac{\text{A}}{\text {(e b)}}[/tex]
c = [tex]\dfrac{1.07}{139.32 \times 1}[/tex] ( ε = 139.32)
c = 0.00768 M
Now, to calculate the percent of the salicylic acid in the solution, we will compare the given concentration of the aspirin.
As we know:
Given mass of aspirin = 0.02 g
Molar mass of aspririn = 240
Number of moles of aspirin = 0.02 / 240 = 8.33 x 10⁻⁵
Now, the molarity of aspirin is:
[tex]\text{Molarity}&= \dfrac{8.33 \times 10^{-5}}{0.01}\\\\\text{Molarity}&= 8.33 \times 10^{-5}[/tex]
Now, the percent of the salicylic acid is:
[tex]\dfrac{\text {C}_1 - \text C}{\text {C}_1 \times 100}[/tex]
[tex]\dfrac{(0.00833 - 0.00768)}{0.00833 \times 100}[/tex]
Percent of Salicyclic acid = 7.8%.
Thus, the percentage of the salicylic acid in the given solution is 7.8%.
To know more about Absorbance, refer to the following link:
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18.35 mL of an HCN solution were titrated with 35.4mL of a 0.268M NaOH solution to reach the equivalence point. What is the molarity of the HCN solution
Answer:
0.517
Explanation:
HCN + NaOH → NaCN + H2O [balanced as written]
(35.4 mL) x (0.268 M NaOH) x (1 mol HCN / 1 mol NaOH) / (18.35 mL HCN) = 0.517 M HCN
Answer: 0.517
Explanation:
What is the hydronium ion concentration of a 0.100 M acetic acid solution with Ka = 1.8 × 10-5? The equation for the dissociation of acetic acid is: CH3CO2H(aq) + H2O(l) ⇌ H3O+(aq) + CH3CO2-(aq) What is the hydronium ion concentration of a 0.100 M acetic acid solution with Ka = 1.8 × 10-5? The equation for the dissociation of acetic acid is: CH3CO2H(aq) + H2O(l) ⇌ H3O+(aq) + CH3CO2-(aq) 1.3 × 10-2 M 4.2 × 10-2 M 1.3 × 10-3 M 4.2 × 10-3 M
Answer:
1.3×10⁻³ M
Explanation:
Hello,
In this case, given the dissociation reaction of acetic acid:
[tex]CH_3CO_2H(aq) + H_2O(l) \rightleftharpoons H_3O^+(aq) + CH_3CO_2^-(aq)[/tex]
We can write the law of mass action for it:
[tex]Ka=\frac{[H_3O^+][CH_3CO_2^-]}{[CH_3CO_2H]}[/tex]
Of course, excluding the water as heterogeneous substances are not included. Then, in terms of the change [tex]x[/tex] due to the dissociation extent, we are able to rewrite it as shown below:
[tex]1.8x10^{-5}=\frac{x*x}{0.100-x}[/tex]
Thus, via the quadratic equation or solve, we obtain the following solutions:
[tex]x_1=-0.00135M\\x_2=0.00133M[/tex]
Obviously, the solution is 0.00133M which match with the hydronium concentration, thus, answer is: 1.3×10⁻³ M in scientific notation.
Regards.
Answer:
1.3×10^-3 M
Explanation:
Step 1:
Data obtained from the question:
Equilibrium constant (Ka) = 1.8×10^-5
Concentration of acetic acid, [CH3COOH] = 0.100 M
Concentration of hydronium ion, [H3O+] =..?
Step 2:
The balanced equation for the reaction.
CH3CO2H(aq) + H2O(l) ⇌ H3O+(aq) + CH3CO2-(aq)
Step 3:
Determination of concentration of hydronium ion, [H3O+].
This can be obtained as follow:
Ka = [H3O+] [CH3CO2-] / [CH3CO2H]
Initial concentration:
[CH3COOH] = 0.100 M
[H3O+] = 0
[CH3CO2-] = 0
During reaction
[CH3COOH] = – y
[H3O+] = +y
[CH3CO2-] = +y
Equilibrium:
[CH3COOH] = 0.1 – y
[H3O+] = y
[CH3CO2-] = y
Ka = [H3O+] [CH3CO2-] / [CH3CO2H]
1.8×10^-5 = y × y / 0.1
Cross multiply
y^2 = 1.8×10^-5 x 0.1
Take the square root of both side
y = √(1.8×10^-5 x 0.1)
y = 1.3×10^-3 M
[H3O+] = y = 1.3×10^-3 M
Therefore, the concentration of the hydronium ion, [H3O+] is 1.3×10^-3 M
if a sample of gas at 25.2 c has a volume of 536mL at 637 torr, what will its volume be if the pressure is increased to 712 torr?
What is the symbol for the entity that has 17 protons, 20 neutrons, and 18 electrons?
hEy!!!
Chlorine(CL) is the symbol for the entity that has 17 protons,20 neutrons and 18 electrons.
Hope it will be helpful to you...
Answer:chlorine
Explanation:
How to make isopropyl alcohol
Answer:
.It is easily synthesized from the reaction of propylene with sulfuric acid, followed by hydrolysis. Isopropyl alcohol (2-propanol) is made by indirect hydration of propylene (CH2CHCH3).… In some cases the hydration of propylene is carried out in one step, using water and a catalyst at high pressure.
Hope it'll help!
stay safe:)
Based on the diagram below, how much of the excess reactant is left over? *
2 slices of bread and 3 pieces of lunchmeat
2 slices of bread and 2 slices of cheese
2 of lunchmeat and 3 slices of cheese
3 of lunchmeat and 2 slices of cheese
Answer:
3 pieces of lunch-meat and 2 slices of cheese
Explanation:
You have enough bread to make 3 sandwiches
You have enough lunch-meat to make 4 sandwiches
You have enough cheese to make 5 sandwiches
In all you have enough material to make 3 sandwiches
so if you subtract three from each number above you will have no bread, enough lunch-meat to make one sandwich and enough cheese to make two sandwiches
luch-meat for one sandwich is: 3 pieces
Cheese for two sandwiches is: 2 pieces
What are 3 stages of the water cycle are
What is the correct IUPAC name for Ag₂S?
Answer:
Acanthite. MFCD00003406
Explanation:
At what temperature will a gas be, if you allow it to expand from its original volume of 756 mL at 65.0 °C to 1.40 L? (hint volume needs to be the same)
Answer:
120.4 gradius Celcius
Explanation:
Please see the step-by-step solution in the picture attached below.
Hope this answer can help you. Have a nice day!
Helium occupies a volume of 3.8 L at –45°C. What was its initial temperature when it occupied 8.3 L?
Answer:
98.3 gradius Celsius
Explanation:
This problem is solved using the Ideal Gas Equation
pV = nRT
...
Please see the step-by-step solution in the picture attached below.
Hope this answer can help you. Have a nice day!
Two identical light bulbs are connected to a battery in a series circuit.
An ammeter is wired into the circuit at measures a current of the
battery to be 0.5 Amps. The two light bulbs are then wired in parallel.
The ammeter shows that the current:
Answer:
0.10 amps
Explanation:
How many moles
are equal to
4.11x1023
molecules of
CO2?
Explanation:
6.02×1023 culture atoms have a mass of 63.5g. 12.0g. c +23.0g O2__44.0g CO2.(12.0+16.0+16.0=44.0g).1 mol 1 mol. 1 mol number molecules weight
The number of molecules in one mole of carbon dioxide is 6.02 × 10²³. Therefore, the number of moles of carbon dioxide which contains 4.11 × 10²³ molecules is 0.68.
What is Avogadro number ?The number of atoms that constitutes one mole of a substance is called Avogadro number. It is equal to 6.02 × 10²³. Thus, one mole of every elements contains Avogadro number of atoms.
Similarly, one mole of a compound contains 6.02 × 10²³ number of molecules. Thus, one mole of carbon dioxide contains these much molecules.
Given the number of molecules of carbon dioxide = 4.11 × 10²³
Then, no.of moles = number of molecules/ Avogadro number.
no.of moles = 4.11 × 10²³ /6.022 × 10²³ = 0.68.
Therefore, the number of moles of CO₂ that contains 4.11 × 10²³ molecules is 0.68.
Find more on Avogadro number:
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It takes 300 N to move a box 10 meters in 10 seconds. How much power is
required?
A. 30,000 W
B. 100 W
C. 3,000 J
D. 300 W
Plz help
Answer:
Power, P = 300 W
Explanation:
We have,
Force acting on the box to take it is 300 N
It is moved to a distance of 10 m in 10 seconds
It is required to find the power required to move the box. The rate at which work is done is called power required by an object. It can be given by the formula as follows :
[tex]P=\dfrac{W}{t}\\\\P=\dfrac{Fd}{t}\\\\P=\dfrac{300\times 10}{10}\\\\P=300\ W[/tex]
So, the power required is 300 W.
Which of the following describes the change in atomic mass and atomic number during this reaction?
What is the molar mass of ethanol (C2H60)?
Answer:
46.07 g/mol is the molar mass of ethonal
HELP PLEASE ILL GIVE 25 pointsWhich of the following practices could help reduce erosion of water banks? a. buffer strips b. natural fertilizers and pesticides c. decrease in fossil fuel emissions d. all of the above Please select the best answer from the choices provided A B C D
Answer:
A. Buffer strips
Explanation:
The practice that could help reduce erosion of water banks is buffer strips.
What is erosion?Erosion is the action of surface processes that removes soil, rock or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited.
One of the practices that could be used to reduce the effect of erosion is buffer strips.
What buffer strips do is slow and filter storm runoff while helping to hold soil in place.
Learn more on buffer strips here; https://brainly.com/question/26872640
Use the graph to determine which is greater, the heat of fusion or the heat of vaporization. Explain how you used the graph to determine that.
(The substance is water)
Answer:
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ds
A sample of helium gas at room temperature is compressed from 100 cm3 to 20 cm3. Its new pressure is now 30 cm Hg. What was the original pressure of the gas?
Answer:
6 cm Hg
Explanation:
Boyles Law: P1V1=P2V2
(100 mL)(x)=(20 mL)(30 cm Hg)
x = 6 cm Hg
*Text me at 561-400-5105 for private tutoring if interested: I can do homework, labs, and other assignments :)
4. A taxi ride costs $5 plus .75 cents per mile. If I
ride for 120 miles, how much will be charged?
Answer:
$95
Explanation:
.75 x 120 = 90
90+5 = 95
If a solution has a pOH=12, what is its pH?
Answer:
2
Explanation:
pH+pOH=14
- Hope that helps! Please let me know if you need further explanation.
Answer:
2
Explanation:
Ph+PoH=14
The largest contributed to water pollution is
Answer:
this si from google hope it helps
Explanation:
The Main Causes of Water Pollution in the U.S.
Runoff from Agricultural Operations. Agriculture represents one of the biggest sources of water pollution in the country. ...
Runoff and Nonpoint Source Pollution. ...
Industrial Activities. ...
Leakage from Underground Storage and Piping. ...
Leaking Sewers. ...
Vehicle Emissions. ...
Landfill Leakage. ...
Hazardous Waste.
Answer:
Runoff and Non-point Source Pollution.
Explanation:
it's caused by rainfall or snow-melt moving over and through the ground. As the runoff moves, it picks up and carries away natural and human-made pollutants, finally depositing them into lakes, rivers, wetlands, coastal waters and ground and NPS is it's abbreviation.
The change in entropy, ΔS∘rxn , is related to the the change in the number of moles of gas molecules, Δngas . Determine the change in the moles of gas for each of the reactions and decide if the entropy increases, decreases, or has little or no change. A. 2H2(g)+O2(g) ⟶ 2H2O(l) Δngas= mol The entropy, ΔS∘rxn , increases. decreases. has little or no change.
Explanation:
Entropy of a reaction ΔS∘rxn is the degree of disoderliness in a system. Gases generally have a higher degree of disorder compared to liquids. Hence for the reaction 2H2(g)+O2(g) ⟶ 2H2O(l), the entropy decreases sice the reactants are in the gaseous state and the products is in the liquid state of matter
5) Low iron concentration (as low as 0.02 nM) in the open ocean limits phytoplankton growth. Preconcentration is required to determine such low concentrations. Trace Fe3 from a large volume of seawater is concentrated onto a 1.2 mL chelating resin column, the column is then rinsed with 30 mL of high purity water and eluted with 10 mL of 1.5 M high purity HNO3. a.) For each sample, seawater is passed through the column of 17 h at 10 mL./min. How much is the concentration of Fe3 in the 10 mL of HNO3 eluate increased by this preconcentration procedure
Answer:
Check the explanation
Explanation:
Sample volume V= 10 mL/min x 17 h x 60 min/h / 1000 mL/L = 10.2 L
The concentration is increased
10200 mL (sample volum) / 10 mL (eluted sample) = 1020 times.
57x10-9 M / 1020 = 5.6x10-12 M
1.5 M HNO3 will contain ≤ 2ppm x (1.5M/15.7M ) ≤ 0.190 ppm ≤ 190 ppb
Ignoring this is reagent impurity and calculating for sea water
≤ 190 ppb /1020 = 0.186 ppb = 0.186 x 10-9g/mL = 0.186 x 10-6g/L =
0.186 x 10-6g/L / 56 g/mol = 0.003 x10-6 M = 3 nM
What is the molarity of sodium hydroxide solution made by combining 2.0 L of 0.60
NaOH With 495 mL 3.0 M NaOH? Assume the volumes of the two solutions to be additive___M
Answer:
[tex]M=1.1M[/tex]
Explanation:
Hello,
In this case, since we are mixing two NaOH solutions, the first step is to compute the total moles once the mixing is done, by using the volumes and concentrations of each solutions and subsequently adding them:
[tex]n_T=2.0L*0.60\frac{mol}{L}+495mL*\frac{1L}{1000mL}*3.0\frac{mol}{L}= 2.7molNaOH[/tex]
Next, we compute the total volume by adding the volume of each solution:
[tex]V_T=2.0L+495mL*\frac{1L}{1000mL}= 2.495L[/tex]
Finally, we compute the molarity of the resulting solution by the division between the total moles and the total volume:
[tex]M=\frac{2.7mol}{2.495L}\\ \\M=1.1M[/tex]
Best regards.
When you add a controlled amount of substance known as an impurity to a pure semiconductor, its conductivity increases. This process is known as doping. The addition of an impurity can increase or decrease the number of available electrons. If the number of electrons is increased, the extra electrons conduct electricity. If the number of electrons is decreased, a vacant hole is created. The adjacent electron enters the vacant hole and conducts electricity. Thus, it seems like the holes act as charge carriers. They are considered to be positive charge carriers. Depending upon the charge carriers that conduct electricity, there are two types of semiconductors: p-type semiconductors and n-type semiconductors.Which of the following statements are correct with respect to semiconductors?
a) The addition of group 3A elements to group 4A semiconductors decreases the conductivity of the group 4A semiconductors.
b) The conductivity of semiconductors can be increased by the doping process.
c) As the temperature increases, the conductivity of semiconductors decreases.
d) The addition of group 5A elements to group 4A semiconductors increases the conductivity of the group 4A semiconductors.
e) Holes are charge carriers in p-type semiconductors.
f) Electrons are charge carriers in n-type semiconductors.
Answer:
See explaination
Explanation:
1. The addition of group 3A elements to group 4A semiconductors decreases the conductivity of the group 4A semiconductors: Wrong
The addition of 3A group elements inreases the conductivity and make them extrinsic semiconductors( p-type)
2. The conductivity of semiconductors can be increased by the doping process.: Correct
3.As the temperature increases, the conductivity of semiconductors decreases.. wrong
As the temperature increases, the conductivity of semiconductors increases.
4. The addition of group 5A elements to group 4A semiconductors increases the conductivity of the group 4A semiconductors: Correct : They will create n-type semicoductor.
5.Holes are charge carriers in p-type semiconductors: Correct
6. Electrons are charge carriers in n-type semiconductors: Correct
Which diagram correctly describes the changes that occur as a small piece of rock falls from space and hits the earth
Answer:
the motion of gravity
Explanation:
Answer:
its c
Explanation
advhuosijoklxcmnjdabsuhggggabciaciudeifweingivg eygerigsygfe97rsghisdcvhbsduigwiugfu9uigdgiurfgyisdgfsdgfegiygewifgsdygfewusgfuyesigf7wgfiesgfiusgdfies
The glass of a lit 75-watt incandescent bulb is hotter to the touch than the glass of a 25-watt compact fluorescent (CFL) bulb that emits the same amount of light. What could be a reason for this
What is the mass defect of a mole of nuclei with 1.8 x 10^15 J/mol binding
energy?
Answer:
2.0 x 10^-2 kg/mol
Explanation:
If you start with 64g of a radioactive element how many half-lives would occur before 8g remain?
Answer:
3 half-lives
Explanation:
The half-life is the time that it takes to a radioactive element to decay to half of its initial amount.
Let's suppose we start with 64 g of the radioactive element.
After 1 half-life, the mass of the element will be 32 g.After 2 half-lives, the mass of the element will be 16 g.After 3 half-lives, the mass of the element will be 8 g.
At constant pressure, what generally happens to the solubility of solids and gases when the temperature of a solution is increased?
A. The solubility of solids and gases increases.
B. The solubility of solids and gases decreases.
C. The solubility of solids increases, and the solubility of gases decreases.
D. The solubility of solids decreases, and the solubility of gases increases.
Answer:
C)
Explanation:
JUST DID IT
Answer:
A D E
Explanation:
just did it
