You weighed out 0.020 g of your crude aspirin product in order to determine the amount of salicylic acid impurity. Following the procedure outlined in the manual, you dissolved the solid and diluted the solution to a final volume of 10.0 mL. If the absorbance of your sample solution was 1.07, what was the percent salicylic acid in your product?
a. 6.4%.
b. 10%.
c. 7.8%.
d. 92%.
e. none of the above.
Answer:
7.8%
Explanation:
Given that:
The initial mass amount of aspirin = 0.020g
The standard molar mass of aspirin = 240 g/mol
Thus, the number of moles = mass/molar mass
= 0.020/240
= 0.0000833 moles
Now, the molarity of aspirin in the solution(diluted) [tex]C_1[/tex] = [tex]\dfrac{8.33 \times 10^{-5}}{0.01}[/tex]
= [tex]= 8.33 \times 10^{-3} \ M[/tex] (provided the volume v = 0.01 L)
The absorbance of the sample solution A =1.07
The path length (b) = 1 cm
From the standard value of salicylic acid, the coefficient (e)= 139.322 /M/cm
Now; according to Beer's law, the concentration of aspirin is:
A = e×b×c
[tex]c = \dfrac{A}{eb}[/tex]
[tex]c = \dfrac{1.07}{139.322 \times 1}[/tex]
c = 0.00768 M
Finally, relating the concentration of the aspirin, the percentage of salicylic acid the product [tex]= \dfrac{0.00833-0.00768}{0.00833} \times 100[/tex]
= 7.8%
A system performed 145 kJ of work on the surroundings and absorbed 105 kJ of heat from the surroundings. What is the change in energy of the system?
Answer:
250 kJ
Explanation:
Step 1: Given data
Work performed by the system (w): 145 kJ (By convention, when the system performs work on the surroundings, w > 0)Heat absorbed by the system (q): 105 kJ (By convention, when the system absorbs heat from the surroundings, q > 0)Step 2: Calculate the change in the internal energy of the system
The internal energy of a thermodynamic system is the energy contained within it. We can calculate the change in the internal energy (ΔE°) using the following expression.
ΔE° = q + w
ΔE° = 105 kJ + 145 kJ = 250 kJ
15 points! Answer only if you can please!
1. Have you ever grabbed the handle of a hot metal pan? Why did it feel hot to you?
2. What would happen if a person who is wearing a heavy winter jacket were to place a thermometer inside the jacket next to his or her skin? What would happen if we took the same jacket, after it had been hanging in a closet, and placed a thermometer inside?
3. How do you think the transfer of thermal energy causes unpopped popcorn kernels to pop?
Answer:
1. Yes
2. it would be the same i guess
3. because it travels to popcorn kernels with its heat and makes it pop'
did i get it right?
Explanation:
Which of the atoms below are least likely to violate the octet rule?
Answer:
F i think i pretty sure F!!!!!!!!
Need help plz asap!!!!
what is protein denaturation
Answer:
Denaturation is a process in which proteins or nucleic acids lose the quaternary structure, tertiary structure, and secondary structure which is present in their native state, by application of some
Explanation:
This item is used for small cuts and peeling.
1-Chef Knife
2-Pizza Cutter
3-Kitchen Shears/Scissors
4-Paring Knife
In an industrial process ethanol C2H60 burns with O2 to produce heat. Each mole of ethanol produces 8842 joules during the reaction.
C2H5OH (1) + 3 O2(g) 2 CO2(g) + 3 H2O(0) + 8842 Joules
How many Kilojoules are obtained from burning 982.6 g of ethanol?
Answer:
[tex]189kJ[/tex]
Explanation:
Hello!
In this case, since one mole of ethanol release 8,842 J per 1 mole of ethanol, we can write:
[tex]\frac{8,842J}{1molC_2H_6H}[/tex]
Thus, since we need the energy released by 982.6 g of ethanol, we compute the moles in such mass of fuel:
[tex]n=982.6g\frac{1mol}{46.08g} =21.3mol[/tex]
Therefore, the result is:
[tex]\frac{8,842J}{1mol}*21.3mol=188,545J[/tex]
Which in kJ is:
[tex]189kJ[/tex]
Best regards!
Why is a “spark” of energy required to begin the chemical reaction of burning a fossil fuel? What is another name for this spark of energy?
Answer: a burst
Explanation: a burst of energy could be substatuded for spark of energy
A spark of energy is required to begin the chemical reaction of burning a fossil fuel because; This spark of energy is required to attain the activation energy of the reaction.
Another name for this spark of energy is Ignition.
Definition:
The activation energy of a chemical reaction is the minimum amount of energy required for the commencement of the chemical reaction.
In this case, the spark of energy is required to attain the activation energy of the reaction.
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a gas occupies 600.0 ml at 20.00 degrees C and 70.00kPa what will be the pressure at 40.00 degrees C and 150.0mL?
Answer:
P₂ = 299.11 KPa
Explanation:
Given data:
Initial volume = 600 mL
Initial pressure = 70.00 KPa
Initial temperature = 20 °C (20 +273 = 293 K)
Final temperature = 40°C (40+273 = 313 K)
Final volume = 150.0 mL
Final pressure = ?
Formula:
P₁V₁/T₁ = P₂V₂/T₂
P₁ = Initial pressure
V₁ = Initial volume
T₁ = Initial temperature
P₂ = Final pressure
V₂ = Final volume
T₂ = Final temperature
Solution:
P₂ = P₁V₁ T₂/ T₁ V₂
P₂ = 70 KPa × 600 mL × 313 K / 293K ×150 mL
P₂ = 13146000 KPa .mL. K /43950 K.mL
P₂ = 299.11 KPa
The molecular mass of propanoic acid is 75.1 amu . Calculate the molecular mass of methyl ethanoate, an isomer of propanoic acid.
Express your answer with the appropriate units.
Answer:
75.1
Explanation:
The isomers contains the similar and accurate chemical formulas but at the same time the structure of the molecular is different. This represents that the masses of the molecular would be similar
Therefore the molecular mass of methyl ethanoate, i.e. an isomer propanoic acid is 75.1 i.e. equivalent to the molecular mass of the propanoic acid
So, it should be 75.1
What is the final pressure of 1.00 mol of ammonia gas, initially at 1.00 atm, if the volume is:___________.
a. gradually decreased from 78.0 mL to 39.0 mL at constant temperature.
1) 2.00 atm
2) 1.00 atm
3) 0.50 atm
4) Not enough data
b. increased from 43.5 mL to 65.5 mL at constant temperature.
c. decreased by 40% at constant temperature.
Answer:
The correct answer is a = 2 atm, b = 0.66 atm, and c = 1.66 atm.
Explanation:
a. When the temperature is constant, the ideal gas equation, that is, PV = nRT becomes PV = constant, or P1V1 = P2V2
Based on the given information, the pressure of the gas is 1.00 atm, the V1 of the gas is 78 ml, and the V2 of the gas is 39 ml.
Now using the above formula we get,
P2 = (P1V1) / (V2)
P2 = 1 atm * 78 ml/39 ml
P2 = 2 atm.
b) Now the volume V1 is 43.5 ml, and the volume V2 is 65.5 ml at constant temperature, P1 is 1 atm. Now P2 will be,
P2 = (P1V1) / (V2)
P2 = 1 atm * 43.5 ml/65.5 ml
P2 = 0.66 atm
c) In the given case, when the volume is decreased by 40 percent, let us consider that the volume, V1 be 100 ml, and the volume V2 be 60 ml, the P1 is 1 atm, now the P2 will be,
P2 = (P1V1) / (V2)
P2 = 1 atm * 100 ml/60 ml
P2 = 1.66 atm.
Humans have 50 pairs of chromosomes true or false
Answer:
False
Explanation:
humans have 23 pairs
what is the volume of 18.9 g of a liquid that has a density of 0.956 g/ml
HELP ASAPPPP BRAINLIEST
Answer:
2nd option
Explanation:
Suggest a possible mechanism for the acid catalyzed reaction of a typical ketohexose to give 5-hydroxymethylfurfural.
Answer:
See explanation
Explanation:
Taking the acid catalysed hydrolysis of fructose C6H12O6, the mechanism begins with the protonation of an -OH group as shown.
This is now followed by dehydration and formation of a keto-enol tautomer. The keto form is now dehydrated followed by the protonation of a second -OH group.
A second dehydration followed by deprotonation leads to the formation of 5-hydroxymethylfurfural.
Image credit: SciElo
The reaction between calcium carbonate (CaCO3) and HCl produces calcium chloride (CaCl2), carbon dioxide (CO2), and water (H2O).What happens when the concentration of hydrogen chloride (HCl) molecules is doubled in this reaction?
CaCO3 + 2HCl → CaCl2 + CO2 + H2O
Answer:
yes that is right
Explanation:
Answer: what is the answer im on plato
Explanation:
Help! I dont know how to do this lol
the order is :
- Aufbau principle
- Hund's Rule
- Pauli's Exclusion Principle
Pro
∆G0=-RT in k Known as
Answer:
Gibbs free energy equation
Explanation:
Need help with this please thanks
Answer: 1. [tex]2H_2+O_2\rightarrow 2H_2O[/tex]
2. [tex]P_4+3O_2\rightarrow 2P_2O_3[/tex]
3. [tex]N_2+3H_2\rightarrow 2NH_3[/tex]
4. [tex]2K+Cl_2\rightarrow 2KCl[/tex]
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The given equations are balanced as:
1. [tex]2H_2+O_2\rightarrow 2H_2O[/tex]
2. [tex]P_4+3O_2\rightarrow 2P_2O_3[/tex]
3. [tex]N_2+3H_2\rightarrow 2NH_3[/tex]
4. [tex]2K+Cl_2\rightarrow 2KCl[/tex]
which two changes of state can be caused by removing thermal energy from a substace A. deposition B. condencation C. vaporization D.sublimation
Answer:
maybe is b but wait to other people answer
Answer:A. deposition B. condencation
Explanation:
Which reaction takes place in a nuclear fission reactor?
C+HN
2 Put He → Cm
OCO+ He-Cot 'n
o U+ nKr+Ba+3'n
Answer:
The reaction that takes place in a nuclear fission reactor is answer D.
Explanation:
Step-by-step explanation:
Nuclear fission reactions involves the process by which large atomic nuclei are bombarded with energetic particles and release of an enormous amount of nuclear energy, which mainly ends up as heat energy.
So now, consider the nuclear reaction from D, after the uranium nucleus absorbs the neutron its split into two smaller nuclei (often radioactive themselves), Krypton and Barium and releases more neutrons (or energy).
Why are a molecule's atoms as far away from each other as they can get?
A) Electronegativity differences force the atoms apart
B) The protons in the nuclei push the atoms apart
C) Forces between electron pairs push the atoms apart
D) Induced dipoles push the atoms away from each other
Answer:
the answer is a
Explanation:
an electron contains a negative charge and like charges repel each other. Hence, in a atom the force of repulsion between the atoms away from each other. As a result a molecules atoms are as far away from each others as they can get .
A molecule's atoms as far away from each other as they can get because "Forces between electron pairs push the atoms apart".
So, option C is correct one.
Why electrons repel each other?Since, an electron is negative charge species revolve around the nucleus of an atom. So, when two atoms come close to each other in molecules there is repulsion occurs between negative charge electron .
To learn more about electrons here.
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HELP IM CONFUSED I GIVE BRAINLIEST
Answer:
I⁻ , Sr²⁺ , K⁺
Explanation:
refer to the periodic table and memorize trends in charges.
What is the structural formula of CF2Br2
Answer:
Dibromodifluoromethane
Explanation:
which of the following is an isotope of hydrogen
What are capacitors used for
Someone took the last cookie from the cookie jar last night. The last person to leave the scene is the culprit. Who was it? Highlight the guilty culprit based on the clues provided.
Can someone help me and explain why they got what they got?
Answer:
24.32 amu
Explanation:
From the question given above, the following data were obtained:
Isotope A (Mg–24):
Mass of A = 24 amu
Abundance (A%) = 79%
Isotope B (Mg–25):
Mass of B = 25 amu
Abundance (B%) = 10%
Isotope C (Mg–26):
Mass of C = 26 amu
Abundance (C%) = 11%
Average atomic mass of Mg =?
Average atomic mass = [(Mass of A × A%)/100] + [(Mass of B × B%)/100] + [(Mass of C × C%)/100]
= [(24 × 79)/100] + [(25 × 10)/100] + [(26 × 11)/100]
= 18.96 + 2.5 + 2.86
= 24.32 amu
Thus, the average atomic mass of Mg is 24.32 amu
Can someone answer 5 for me please?
Answer:
D
Explanation:
D