Direct ethanol fuel cells (DEFCs) have shown some promise as a viable option for providing "green" energy to small electrical devices. Calculate E° for the reaction that takes place in DEFCs:

C2H5OH(l) + 3O2(g) → 2CO2(g) + 3H2O(l)
Use the following values.

∆G°H2O(l) = -237 kJ/mol
∆G°O2(g) = 0 kJ/mol
∆G°CO2(g) = -394 kJ/mol
∆G°C2H5OH(l) = -175 kJ/mol.
Eo = ? V

Answers

Answer 1

The emf of the cell from the reactions and the change in free energy is 2.8 V.

What is the Eocell?

The Eocell refer to the emf of the cell under standard conditions. In this case, it can be obtained from the free energy of the values of the reactants and products.

Now, given; C2H5OH(l) + 3O2(g) → 2CO2(g) + 3H2O(l)

ΔG°rxn = [2(-394) + 2( -237)] - [( -175 ) + 0 ]

= [(-788) + (-474)] + 175

= -1087  kJ/mol

Also;

ΔG° = -nFEocell

Eocell  = ΔG° /-nF

Eocell  = -1087  * 10^3/-(4 * 96500)

Eocell  =-1087  * 10^3/386000

= 2.8 V

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Related Questions

define concentration and give examples.​

Answers

Answer:

Concentration: The amount of a given substance within a set solution.

Explanation:

For example, the units for concentration include mol/[tex]dm^{3}[/tex] which means that if a substance has 3 mol/[tex]dm^{3}[/tex], it means 3 moles of that substance is in a 1 dm cubed of that solution. You could give examples of the concentration of acids like Hydrochloric Acid (HCl) and alkalis like Hydroxide (OH).

What is the phase of water at 1.0 atm and 50°C?
Water
(liquid)
Water vapor
(gas)
100
Temperature (°C)
Pressure (atm)
1-
0.5-
0.25-
0
Ice
(solid)
-10
OA. Liquid and gas
OB. Liquid
OC. Solid
D. Gas
0-
0.01

Answers

The given temperature of water is 50 degrees Celsius, hence, we can conclude that the phase of the given water is liquid phase.

What is phase of water?

Water can exist in three different phases, namely;

Liquid phase - usually between 0 to 100 degrees CelsiusSolid phase - below 0 degrees CelsiusVapor phase or gaseous phase - usually above 100 degrees Celsius

Therefore, if the given temperature of water is 50 degrees Celsius, hence, we can conclude that the phase of the given water is liquid phase.

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Joel reacted 0.9845 g of iron filings with an excess of copper sulphate solution. When the reaction was complete the solution had changed from blue to green and a copper deposit weighing 1.024 g had formed in the solution. In this reaction, metallic iron is converted into ferrous ion (Fe2+) and cupric ion (Cu2+) is converted into metallic copper.


a) Calculate the number of moles of iron used and the number of moles of copper

formed.


b) Calculate the theoretical mass of copper that was expected to be produced and

hence deter,mine the percentage yield of Joel’s experiment.


c) How many molecules of iron are present in 0.9845 g of iron fillings?


Fiona prepared a solution by dissolving 1.35 g of silver nitrate in a 250 mL volumetric flask and diluting it up to the volume.


d) Calculate the molarity of the silver nitrate solution.


e) What volume of this solution is required to prepare 100 mL of 0.01 M of silver nitrate solution?

Answers

From the stoichiometry of the reaction, the percentage yiled of the copper is 89.6%

What is reaction equation?

The reaction equation here is given as; Fe(s) + CuSO4 (aq) ----->FeSO4(aq) + Cu(s)

Number of moles of Fe = 0.9845 g/56 g/mol = 0.018 moles. Since the reaction is 1:1, this is also the number of moles of Cu formed.

Theoretical yiled of Cu =  0.018 moles * 63.5 g/mol = 1.143 g

Percentage yiled =  1.024 g/1.143 g * 100/1 = 89.6%

If 1 mole of Fe contains 6.02 * 10^23 molecules

0.018 moles of Fe contains 0.018 moles *  6.02 * 10^23 molecules/1 mole = 1.1 * 10^22 molecules.

Number of moles of AgNO3 =  1.35 g/170 g/mol = 0.0079 moles

Molarity of the solution = 0.0079 moles/250 * 10^-3 L = 0.0032 M

Hence; 0.0032 M * V1 = 100 mL  *  0.01 M

V1 = 312.5 mL

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A container holds 6.4 moles of gas. Hydrogen gas makes up 25% of the total moles in the container. If the
total pressure is 1.24 atm. What is the partial pressure of hydrogen? Must show work! Use P^a/P^t = n^a/n^t

Answers

Answer:

i let alone need more time to figure this out and i will get you the awnser.

Explanation:

What is the molar mass of K₂CO₃?

Answers

Answer:

138g/mol

Explanation:

K₂CO₃ is also known as potassium carbonate. It has a molar mass of around 138.21 g/mol (138.2055 g/mol to be exact).

(image attached) AP CHEM ACID BASE Is my answer correct? I will mark as brainliest if you answer me. I don't need an explanation if i'm right just explain if i'm wrong. Thanks

Answers

Answer:

Your answer is correct based on what I remember from AP Chemistry  

Explanation:

What inference can be drawn from the graph?
A+B=C+D
45
40
35
30
25
Concentration
20
15
10
5
0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Time (seconds)
OA. The reaction between A and B is reactant favored.
OB. The amount of product is greater than the amount of reactant.
OC. The reaction uses all its reactants to form products.
OD. The reaction reaches equilibrium at 1.5 seconds
OE. The amount of reactants is highest at equilibrium.

Answers

Answer:

i think its C

Explanation:

The graph indicates that the reaction reaches equilibrium around 1.5 seconds. The graph shows how the concentrations of reactants and products change over time until they eventually become constant. So, the correct option is D.

What is an Equilibrium?

Equilibrium is a state in a chemical process when forward and backward reactions occur at the same rate, meaning that the concentrations of reactants and products do not change with time. In other words, the forward reaction rate equals the reverse reaction rate.

In the example above, the graph indicates that the reaction reaches equilibrium in about 1.5 seconds. The graph shows how the concentrations of reactants and products change over time until they eventually become constant. This indicates that the reaction has reached equilibrium when obtained in approximately 1.5 seconds.

So, the correct option is D.

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7. In the process of assembling bicycles, you have 114 frames, 300 tires, 75 seats, 109 sets of pedals, and 84 sets of handlebars. Which is the limiting reactant in this process?
a. frames
c. seats
e. handlebars
b. tires
d. pedals

Answers

In the bicycle assembling process, the limiting reactant is seats since they will be used up first.

What is a limiting reactant?

A limiting reactant is a reactant which is used up first in a reaction and on which product formation depends on.

In a given reaction, once the limiting reactant is used up, the reaction will stop.

For a bicycle to be assembled, 1 frame, 1 seat, 1 seat of handlebars, 1 seat of pedals and 2 tires are required.

In the process of assembling bicycles, there are 114 frames, 300 tires, 75 seats, 109 sets of pedals, and 84 sets of handlebars.

Therefore, the limiting reactant is seats since they will be used up first.

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Calculate the volume of hydrogen gas at 38.0 °C and 763 torr that can be produced
by the reaction of 4.33 g of zinc with excess sulfuric acid.

Answers

solution:

formula= PV = nRT

moles of Zn = 4.33 g Zn x 1 mol Zn/65.4 g

= 0.0662 moles Zn

moles H2 = 0.0662 moles Zn x 1 mol H2/mol Zn

= 0.0662 mole H2 gas

V = nRT/P

T = 38 + 273

= 311K

763 torr/760

= 1.00 atm

V = (0.0662 mol)(0.0821 Latm/Kmol)(311K)/1.00 atm

V = 1.69 L

Which best describes the law
of conservation of mass?
• The coefficients in front of the chemicals in
the reactants should be based on the physical state of the products.
O Products in the form of gases are not considered a part of the total mass change from reactants to products.
• When reactants contain both a solid and a liquid, the solid counts toward the overall mass and the liquid does not.
• The mass of the reactants and products is
equal and is not dependent on the physical state of the
substances.
Mark this and retum
Save and Exit
Next
Submit

Answers

Answer:

The mass of the reactants and products is

equal and is not dependent on the physical state of the

substances.

The specific heat of water is 1.0 calorie/ gram °C. The amount of heat energy needed to raise the temperature of 450 grams of water from 25 °C to 55 °C is: O 15 calories​

Answers

Answer:

Explanation:

We can use the equation to find out

E = mc△T

E is the total energy (calories) needed, m for mass, c for specific heat capacity and △T for the temperature change.

Substitute the numbers given

E = 500 x 1 x 10

E =5000

Therefore the answer is 5000CalWe can use the equation to find out

E = mc△T

E is the total energy (calories) needed, m for mass, c for specific heat capacity and △T for the temperature change.

Substitute the numbers given

E = 500 x 1 x 10

E =5000

Therefore the answer is 5000Cal

What is the standard enthalpy change for the reaction:

3NO2(g)+H2O(l)→2HNO3(aq)+NO(g)
Use standard enthalpies of formation in your textbook.

Select one:

a.
-66.2 kJ


b.
-138 kJ


c.
-116 kJ


d.
-201 kJ

Answers

I have a gut feeling it’s a, and I’m a middle so trust me

8. Choose the compound that is metallic.
P4010

NaCI

FE

Answers

Your answer is FE, or iron!

what as the cause of wrld war 2?

Answers

Answer:

because peoples don't has so mu thinking power that time

[tex]\bold{Heya!}[/tex]

Wowie- nice cat... plus, he or she is fluffy...

Have a great day!

#LearnWithBrainly

[tex]\underline{Answer :}[/tex]

XxVioletXx

23) A common reaction that occurs in cells is shown here. In the presence of oxygen, a glucose molecule is combusted to form carbon dioxide and water. If 360 grams of glucose are combusted fully,
calculate how many moles of oxygen gas will be needed to achieve this reaction.
A) 2
B) 8
C)12
D) 18

Answers

Answer:

C

Explanation:

add them together and multiply by 2

1) Sodium hydroxide is deliquescent. A sample of 3.0 g was dissolved in 100 mL; 10 mL was titrated with 34.9 mL HCl 0.2 M. What is the percent of absorbed water in the sample? ​

Answers

From the calculation, the percentage of water in the sodium hydroxide sample is 7%.

What is neutralization?

The term neutralization has to do with the reaction between an acid and a base to yiled salt and water.

Now we have  to apply the titration formula;

CAVA/CBVB = NA/NB

CA = concentration of acid

CB = concentration of base

VA = volume of acid

VB = volume of base

NA = number of moles of acid

NB = number of moles of base

The reaction equation is; HCl + NaOH ----->NaCl + H2O

CAVANB = CBVBNA

CB = CAVANB /VBNA

CB = 34.9 * 0.2 M * 1/10 * 1

CB = 0.698 M

Number of moles = Conncentration * volume

= 0.698 M * 100/1000 L = 0.0698 moles

Mass = Number of moles * molar mass

Mass =  0.0698 moles * 40 g/mol = 2.79 g

percent of NaOH = 2.79 g/ 3g * 100/1 = 93%

Percent of water = 100- 93 = 7%

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APP
Questions
Show all calculations and proper units to earn full marks
1.
Determine the identity of element X in the following nuclear reaction
atomic mass
a) 23°U → He + x
9202 atomic num
b) x
He + 282Pb
206
23go
c)
244 Cm + He
He
&X + 1H + 2an
96
d)
-
23U + x
BU
→ 2450f + 4 ón
Cf
98
10
257Lr + 5 on
+ 1.B →
el ?x
->
103

Answers

Answer:

Explanation:

This question is about nuclear reactions. (a) (i) Define the term unified atomic mass unit. [1]. 1/12th mass of an atom of carbon-12.

The nuclear reaction can be written as: Mg2512+He42→H11+XAZ. where. A is the mass number and; Z is the atomic number of the new nuclide, X.

The mass defect for an isotope was found to be 0.410 amu/atom. Calculate the binding energy in kJ/mol of atoms. (1 J = 1 kg m2/s2): (a) 3.69 x 1010

Consider these reactions:
Reaction 1: H2(g) + Cla (g)
2HC1(g) AH = -184.6 kJ

Reaction 2: 20F2(g)
02(g) + 2 F2(g)
AH = -49.4 kJ

Reaction 3: N2(g) + 202(g)
2N02(g)
AH = +66.4 kJ

Use Reaction 1.

Determine the mass, in grams, of chlorine gas consumed (with excess H-) when
1,342.0 kJ of energy iS released from the system.
Answer: g

Answers

511.2 grams of chlorine gas consumed (with excess H-) when

1,342.0 kJ of energy is released from the system.

What is an exothermic reaction?

In thermochemistry, an exothermic reaction is a "reaction for which the overall standard enthalpy change ΔH⚬ is negative."

Given that 1 mole of chlorine releases -184.6 energy.

Then, we have to find the number of moles of chlorine when 1,342.0 kJ of energy is released from the system.

So, calculating number of moles of chlorine.

Moles = [tex]\frac{-1,342.0 \;kJ}{-184.6\;kJ}[/tex]

Moles = 7.2 mole

Now, calculating number mass of chlorine.

[tex]\rm Moles=\rm\frac{Mass}{Molar \;mass}[/tex]

Mass =  7.2 mole x 71 g/mole

Mass = 511.2 gram

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Question 5 of 5
Which term refers to the average kinetic energy of the particles in a sample of
matter?
OA. Temperature
OB. Potential energy
OC. Heat
OD. Thermal energy
SUBMIT.

Can you pls anwser as soon as u can

Answers

Answer:

Tempreture should be the correct answer!!

Explanation:

hope this helps ya!!

Calculate the volume in liters of 50.0 grams of NO2 at STP.

Answers

First, calculate how many moles of O2 you have:

O is 16g/mole, so O2 is 32g/mole. 50/32 = 1.5625 moles

1 mole of any gas at stp is 22.4 liters

1.5625 × 22.4 = 35 liters.

According to the mole concept, the number of moles in 50 g of NO₂ is 1.086 as molar mass of NO₂ is 46 g and as per STP conditions volume is 24.32 L.

What is a mole?

Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.

It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.

It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons. Molar mass has units of gram per mole . In case of molecules, where molar mass  in grams present in one mole  of atoms is its atomic mass.

Initially the number of moles is calculated as, 50/46=1.086 moles . As 1 mole occupies 22.4 L at STP conditions,1.086 moles occupy 1.086×22.4=24.32 L.

Hence, the volume in liters of 50 g of NO₂ at STP is 24.32 L.

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A 25.0 mL solution of Sr(OH)₂ is neutralized with 31.6 mL of 0.150 M HBr. What is the concentration of the original Sr(OH)₂ solution?

Answers

A 25.0 mL solution of Sr(OH)₂ is neutralized with 31.6 mL of 0.150 M HBr, then the concentration of the original Sr(OH)₂ solution is 0.189M.

How do we calculate the concentration?

Concentration of the solution will be calculated by using the below chemical reaction as:

M₁V₁ = M₂V₂, where

M₁ & V₁ is the molarity and volume of HBr solution and M₂ & V₂ is the molarity and volume of original Sr(OH)₂ solution.

On putting values on above equation by taking from question, we get

M₂ = (0.15)(31.6) / (25) = 0.189 M

Hence required molarity of Sr(OH)₂ solution is 0.189M.

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d. How many molecules of CO2 are produced from 62.4 g
of C10H18

Answers

The number of molecules of CO₂ produced from 62.4 g of C₁₀H₁₈ is equal to 27.099×10²³.

What is Avogadro's number?

Avogadro's number is define as the number of entities present in one mole of any susbtance and it willl be equal to 6.022×10²³.

Moles (n) from mass will be calculated as:
n = W/M, where

W = given mass

M = molar mass

Given chemical reaction will be represented as:

C₁₀H₁₈ + 29/2O₂ → 10CO₂ + 9H₂O

Moles of C₁₀H₁₈ = 62.4g / 138.25g/mol = 0.45 moles

From the stoichiometry of the reaction,

0.45 mole of C₁₀H₁₈ = produces 10×0.45 = 4.5 moles of CO₂

By using the avogadro's formula, molecules of CO₂ will be calculated as:

Molecules of CO₂ in 4.5mol = 4.5 × (6.022×10²³) = 27.099×10²³

Hence required molecules of CO₂ is 27.099×10²³.

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Which type of cell is shown in the following image?

Answers

The answer is prokaryotic

Answer:

A prokaryotic cell is shown in the image

Explanation:

Prokaryotic cells are the most basic types. Since they are basic, they don't have a nucleus. All eukaryotic cells have it but prokaryotic cells don't have it. A nucleus contains organelles such as a mitochondria which the diagram doesn't show as well. Thus a prokaryotic cell is shown in the image.

Which is NOT a disadvantage of using electromagnetism?

A.) cause cancer

B.) damage medical equipment

C.) accurate viewing of soft tissue in the body

D.) heat up quickly

Answers

Answer:

Electromagnetism can cause cancer

So option A is incorrect

Electromagnetism can damage a medical instruments

It is also a disadvantage and this option is not correct

Now come to C it says that electromagnetic is used to veiw the soft tissue it is not a disadvantage but a advantage so C IS THE CORRECT ANSWER

Explanation:

PLEASE MARK ME BRAINLIEST IF MY ANSWER IS CORRECT PLEASE

A 0.30 M solution of formic acid, HCHO 2, is 2.4% ionized. The ionization constant for formic acid is O a. 1.7 X 10-4 O b.7.2 x 10-3 O C.24 X 10-2 O d. 1.6 X 10-5​

Answers

Answer:

help me remove all the scammers on brainly by not clicking on such random scam links

A constant volume of oxygen is heated from 100oC to 185 oC. The initial pressure is 4.1 atm. What is the final pressure?

Answers

A constant volume of oxygen has a pressure of 4.1 atm at 100 °C and 5.0 atm at 185 °C according to Gay-Lussac's law.

What does Gay-Lussac's law state?

At constant volume, the pressure of an ideal gas is proportional to its absolute temperature.

Step 1: Convert the temperatures to the absolute scale.

We will do so by adding 273.15 to the Celsius temperature.

T₁: 100 °C + 273.15 = 373 K

T₂: 185 °C + 273.15 = 458 K

Step 2: Calculate the final pressure of the gas.

We will apply Gay-Lussac's law.

P₁/T₁ = P₂/T₂

P₂ = P₁ × T₂/T₁

P₂ = 4.1 atm × 458 K/373 K = 5.0 atm

A constant volume of oxygen has a pressure of 4.1 atm at 100 °C and 5.0 atm at 185 °C according to Gay-Lussac's law.

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is Al+CuCl2 a spontaneous reaction?

Answers

Answer:

No, it isn't a spontaneous reaction.

Explanation:

A spontaneous reaction is a reaction that requires no outside intervention to start.

All chemical reactions require energy.

mark brainliest please!

Which statement best describes the relationship between ocean CO2 and pH?

Question 3 options:

When CO2 increases, pH increases and acidity decreases.


When CO2 increases, pH decreases and acidity increases.


When CO2 increases, pH decreases and acidity decreases.


There is no relationship between CO2 and pH

Answers

Answer:

The answer is When CO2 increases, pH decreases and acidity increases.

Explanation:

Excess carbon dioxide (CO2) in the atmosphere gets absorbed at the ocean surface of the ocean. This excess CO2 results in more hydrogen ions, which increases the acidity of the ocean.


What is the formula of this
inorganic salt hydrate?





Answers

Salt hydrates are an important class of PCMs. An inorganic salt hydrate (hydrated salt or hydrate) is an ionic compound in which the ions attract a number of water molecules, which are then trapped inside the crystal lattice. A hydrated salt has the generic formula MxNy. nH2O.

When magnesium is added to hydrochloric acid it reacts violently. If 87.0g of magnesium is used during this reaction how much magnesium chloride is produced?

Answers

Answer:

Magnesium hydroxide is a base. Hydrochloric acid, as the name suggests, is an acid.

So an acid and a base together will produce salt and water. In this case, the salt is magnesium chloride.

This process is known as neutralisation

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125% of what number is 476? What change would shift the equilibrium system to the left Solve for a side in right triangles Which of the following statements is false? a. a role model is somone who is admired. b. having role models who discourage drug use can lessen the chance of drug use. c. some media may glamorize or encourage drug use. d. by law, the media must portray drug use accurately and honestly. please select the best answer from the choices provided. a b c d The population parameters that describe the y-intercept and slope of the line relating y and x, respectively, are _____. a. a and b b. B0 and B1 c. y and x d. a and B (THIS IS IN MUSIC, BUT THERE IS NO MUSIC CHOICE.)What are chord progressions?A. ImprovisationB. Feeling of movementC. Rules for playing chordsD. Order in which we play chords I have never been to London into affirmative sentence Unlike the chordates, the other Deuterostome phyla of Echinoderms and Hemichordates are both comprised of ________. marine species tetrapod species detritivores terrestrial species Do you think the State Pension fund ought to be the only fund for retirement? Explain. What would be the key steps to consider if you are thinking about renting your facility to a potential user for an event Based on which of the following signs and symptoms would you determine that a victim is experiencing respiratory distress?. Use the text to compare and contrast natural vanilla and artificial vanilla __________ can involve false beliefs that often involve the individual being harassed or manipulated by others. a. emotional indifference b. social withdrawal c. delusions of grandeur d. delusions of persecution please select the best answer from the choices provided a b c d What is the appropriate distance for social space?. The reserve ratio equals 2 percent. The Fed buys $1 million in U.S. government securities. The most the money supply can increase is a. $10 million. b. $40 million. c. $50 million. d. $100 million. Which of the following functions is graphed below? Astronomers have discovered pulsars spinning 500 x per second or more. How do astronomers think pulsars got to be spinning so outrageously fast -12x - 7=53 ill give brainlies In the society library, there are 3,98,456 old books. The management decided to add 67,876 new books. How many books will be there in library? Much of the art created in the United States in the mid-1800s reflected abelief in:A. the triumph of humans over nature.O B. the power of Catholic beliefs.C. the importance of the individual