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
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%
_Ag2S __Ag +_S8
I need help ASAP
Answer:
8Ag2S 16Ag + S8
Explanation:
HELP IM CONFUSED I GIVE BRAINLIEST
Answer:
I⁻ , Sr²⁺ , K⁺
Explanation:
refer to the periodic table and memorize trends in charges.
Humans have 50 pairs of chromosomes true or false
Answer:
False
Explanation:
humans have 23 pairs
Pro
∆G0=-RT in k Known as
Answer:
Gibbs free energy equation
Explanation:
I need hlep with this question
Answer:
yes its what the other person said
Explanation:
Polonium-214 went through a series of radioactive decays to produce a stable isotope of bismuth-210 choose the correct decay series that would produce bismuth-210
A: Polonium-214 undergoes 2 beta decay and 1 gamma emission
B: Polonium-214 undergoes 1 alpha decay and 2 gamma emission
C: Polonium-214 undergoes 2 alpha decay and 1 beta decay
D: Polonium-214 undergoes 1 alpha decay 1 beta decay and 1 gamma emission.
The correct decay series :
₈₄Po²¹⁴⇒₈₃Bi²¹⁰+₂He⁴+ ₋₁e⁰+ ₀γ⁰
Further explanationRadioactivity is the process of unstable isotopes to stable isotopes by decay, by emitting certain particles,
alpha α particles ₂He⁴ beta β ₋₁e⁰ particles gamma particles ₀γ⁰ positron particles ₁e⁰ neutron ₀n¹Decay's reaction :
₈₄Po²¹⁴⇒₈₃Bi²¹⁰+x+y+z
From this decay reaction can be concluded
mass number decreased by 4
atomic number decreased by 1
Then the most suitable are:
Polonium-214 undergoes 1 alpha decay 1 beta decay and 1 gamma emission.
₈₄Po²¹⁴⇒₈₃Bi²¹⁰+₂He⁴+ ₋₁e⁰+ ₀γ⁰
So that the mass number and atomic number are the same both before and after decay
The observed cell potential for a voltaic cell is 2.067 V when the temperature is 298 K and the concentration of copper(ll) ions is 1.07 M. What is the concentration of aluminum ions in this cell?
Al(s)|A13+ (aq, ?M)||Cu2+(aq, 1.07M)|Cu(s)
Cu2+(aq) + 2 e- → Cu(s) 0.337 V
Al3+(aq) + 3 e- → Al(s) -1.66 V
Answer:
3.22 * 10^-4 M
Explanation:
The cell reaction equation is;
2Al(s) + 3Cu^2+(aq) ------> 2Al^3+(aq) + 3Cu(s)
E° = 0.337 V - (-1.66 V)
E° = 1.997 V
Given that the cell potential is 2.067 V, from Nernst's equation;
E = E° - 0.0592/n log Q
Substituting values;
2.067 = 1.997 - 0.0592/6 log [Al^3+]^2/[1.07]^3
0.07 = - 0.0592/6 log [Al^3+]^2/[1.07]^3
- 7.07 = log [Al^3+]^2/[1.07]^3
Antilog (- 7.07) = [Al^3+]^2/[1.07] ^3
8.5 * 10^-8 = [Al^3+]^2/[1.07]^3
[Al^3+]^2 = 8.5 * 10^8 * 1.07 ^3
[Al^3+]^2 = 1.04 * 10^-7
[Al^3+] = √1.04 * 10^-7
[Al^3+] = 3.22 * 10^-4 M
This item is used for small cuts and peeling.
1-Chef Knife
2-Pizza Cutter
3-Kitchen Shears/Scissors
4-Paring Knife
As the number of bonds increases, the strength of the bond ________.
Answer:
increases
Explanation:
The third law of thermodynamics states that:_____.
a. the entropy of the universe equals the sum of the entropy of system and that of the surroundings.
b. the entropy of the universe is constant.
c. the entropy is zero at 0 K for a perfect crystal.
d. the entropy of the universe is increasing.
e. the absolute entropy of a substance decreases with increasing temperature.
Answer:
C
Explanation:
The third law of thermodynamics states that at absolute zero temperature, the entropy of a perfect crystal is zero. In other words, as the temperature of a system approaches zero, the entropy also approaches a constant value.
The law only holds true only if the crystal has minimal energy and only exist in one state. The entropy becomes zero as the temperature also becomes zero only for a perfect crystal. Otherwise, the law refuses to hold.
The correct option is, therefore, C.
Which statements correctly compare the masses of protons neutrons and electrons
What are capacitors used for
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
Can someone answer 5 for me please?
Answer:
D
Explanation:
D
Which of the atoms below are least likely to violate the octet rule?
Answer:
F i think i pretty sure F!!!!!!!!
What is a mixture?
any substance with a uniform composition
a combination of pure substances bonded chemically
any group of elements that are chemically bonded to one another
a blend of any two or more kinds of matter where each maintains its own unique
properties
Which term describes a mixture that is not uniform through
An atom has two valence electrons, but four shells. This element is a member of which group or family?
A. halogen
B. noble gas
C. alkaline earth metal
D. alkali metal
Need help plz asap!!!!
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.
Read more:
https://brainly.com/question/7639475
which orbital has the highest energy level
Answer:
p orbitals
Explanation:
The image seen here is caused by events __________ Earth's surface.
A) above
B) at
C) on
D) under
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.
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
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
Please help with the chart
Answer:
no
Explanation:
what is the volume of 18.9 g of a liquid that has a density of 0.956 g/ml
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