A hydrogen fuel cell is an electrochemical reactor in which oxygen and hydrogen gas are reacted to produce energy. Rather than combusting hydrogen in the presence of oxygen, the overall reaction (1/2) O2 H2 → H2O is actually carried out as two `half-reactions’ occurring at separate electrodes. To complete the reaction, this forces electrons to pass through an external circuit from one electrode to the other, and this current can be used to do work; e.g., by driving a motor. Typical operating conditions for a solid-oxide fuel cell are 500-900 C and 5-15 bar. Consider a fuel cell in which a pure oxygen stream and a pure hydrogen stream enter at 11 bar and 700 C with stoichiometric flowrates. Assume that these reactants are consumed completely, and that the water generated by the reaction leaves in a third stream at the same T and P. Assume that the fuel cell operates at steady-state with a uniform temperature of 700 C. a) Write simplified first and

Answers

Answer 1

Answer:

(d) Why is the fuel cell in Question (c) described as an alkaline fuel cell? (e) Another type of fuel cell uses methanol instead of hydrogen.

Explanation:


Related Questions

Why do atoms connect to eachother?

Answers

Answer:

To keep from falling apart

Explanation:

To keep from falling apart


2 C8H18 + 25 O2 → 16 CO2 + 18 H2O

How many moles of CO2 can form from 17.5 moles of octane?

Answers

Answer:

140 mol CO₂.

Explanation:

2 C₈H₁₈ + 25 O2 → 16 CO₂ + 18 H₂O

In order to convert from moles of octane (C₈H₁₈) into moles of CO₂, we can use a conversion factor with the stoichiometric coefficients of the balanced reaction:

17.5 mol C₈H₁₈ * [tex]\frac{16molCO_2}{2molC_8H_{18}}[/tex] = 140 mol CO₂

140 moles of CO₂ can be produced from 17.5 moles of octane.

d. If you were to open the carbonated drink bottle after shaking, what would you expect to happen and why? If you were to open the water bottle after shaking, what would you expect to happen and why?

Answers

Shaking causes small bubbles, which helps the soda's carbon dioxide escape faster. The gas will gradually escape from the liquid as bubbles once the can is opened, and the soda will become "flat." The dissolved gas takes a long time to escape if the liquid is treated gently.

In the oxidation of iron; how many grams of iron (III) oxide will be produced from 6.20 mol of Fe?
4Fe(s) + 3O2(g) --> 2Fe2O3(s)

Answers

Answer:

496 g of Fe₂O₃.

Explanation:

The balanced equation for the reaction is given below:

4Fe + 3O₂ —> 2Fe₂O₃

From the balanced equation above,

4 moles of Fe reacted to produce 2 moles of Fe₂O₃.

Therefore, 6.20 moles of Fe will react to produce = (6.20 × 2)/4 = 3.1 moles of Fe₂O₃

Finally, we shall determine the mass of 3.1 moles of Fe₂O₃. This can be obtained as follow:

Mole of Fe₂O₃ = 3.1 moles

Molar mass of Fe₂O₃ = (56 × 2) + (3×16)

= 112 + 48

= 160 g/mol

Mass of Fe₂O₃ =?

Mass = mole × molar mass

Mass of Fe₂O₃ = 3.1 × 160

Mass of Fe₂O₃ = 496 g

Therefore, 496 g of Fe₂O₃ were produced from the reaction.

An allele is a form of a gene? true or false

Answers

Answer:

true

Explanation:

Theses are all the points
I have left

Would you rather Go to jail for the rest of your life or go to prison for the rest of you life?

Answers

Uhhhh... iD rAtHeR gO tO pRiSoN

Thanks for the points!!! ( ^ω^ )

Answer:

I honestly don't know but I hope you get more points! ;D

Explanation:

.) Neon and HF have approximately the same molecular masses. a.)Explain why the boiling points of Neon and HF differ b.)Compare the change in the boiling points of Ne, Ar, Kr, and Xe with the change of the boiling points of HF, HCl, HBr, and HI, and explain the difference between the changes with the increasing atomic or molecular mass.

Answers

Answer:

See explanation

Explanation:

a) The magnitude of intermolecular forces in compounds affects the boiling points of the compound. Neon has London dispersion forces as the only intermolecular forces operating in the substance while HF has dipole dipole interaction and strong hydrogen bonds operating in the molecule hence HF exhibits a much higher boiling point than Ne though they have similar molecular masses.

b) The boiling points of the halogen halides are much higher than that of the noble gases because the halogen halides have much higher molecular masses and stronger intermolecular forces between molecules compared to the noble gases.

Also, the change in boiling point of the hydrogen halides is much more marked(decreases rapidly)  due to decrease in the magnitude of hydrogen bonding from HF to HI. The boiling point of the noble gases increases rapidly down the group as the molecular mass of the gases increases.

Calculate the pH of a 0.10 M NH4Cl solution.

Answers

Answer:

Answer: pH = 2.72

Explanation:

Calculate the pH of 0.010 M HNO2 solution. The K, for HNO2 is 4.6 x 104 

What is the molecular geometry of COF2?

Answers

Answer:

trigonal planar

Explanation:

What is most likely oxidation state of aluminum (AI)?

Answers

Aluminum has three oxidation states. The most common one is +3. The other two are +1 and +2. One +3 oxidation state for Aluminum can be found in the compound aluminum oxide, Al2O3.

A student prepared a stock solution by dissolving 20.0 g of NaOH in enough water to make 150. mL of solution. She then took 15.0 mL of the stock solution and diluted it with enough water to make 65.0 mL of a final solution. What is the concentration of NaOH for the final solution

Answers

Answer:

[tex]0.769\ \text{M}[/tex]

Explanation:

Mass of stock solution = 20 g

Molar mass of NaOH = 40 g/mol

Volume of stock solution = 0.150 mL

[tex]M_2[/tex] = Concentration of NaOH for the final solution

[tex]V_1[/tex] = Amount of stock solution taken = 15 mL

[tex]V_2[/tex] = Total volume of solution = 65 mL

Molarity is given by

[tex]M_1=\dfrac{\text{Mass}}{\text{Molar mass}\times \text{Volume}}\\\Rightarrow M_1=\dfrac{20}{40\times 0.15}\\\Rightarrow M_1=\dfrac{10}{3}[/tex]

We have the relation

[tex]M_1V_1=M_2V_2\\\Rightarrow M_2=\dfrac{M_1V_1}{V_2}\\\Rightarrow M_2=\dfrac{\dfrac{10}{3}\times 15}{65}\\\Rightarrow M_2=0.769\ \text{M}[/tex]

The concentration of NaOH for the final solution is [tex]0.769\ \text{M}[/tex].

cosity a letter to our mother
who is in lagos Nigeria telling
her about the
the problem you are
facing
in the school and at
home and suggest solution to
you pproblem

Answers


An answer befitting your question…

Hi mom, I’m having troubles with my teachers. They are cruel to me and I cannot concentrate. I think if we changed schools it would be much better. Thank you mom.

⚠️LINKS WILL BE REPORTED⚠️ // Need answers as fast as possible!

- Electrons always fill orbitals in the same order. Each s orbital holds 2 electrons, each set of p orbitals holds 6 electrons, each set of d orbitals holds 10 electrons, and each set of f orbitals holds 14 electrons. The order in which orbitals are filled, from first to last, is:

1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f 6d 7p

Beryllium has 4 electrons. What is the electron configuration of beryllium?

A.
2s^22p^2
B.
1s^22s^2
C.
2s^4
D.
4p^1

Answers

Answer:

[tex]1s^2\, 2s^2[/tex].

Explanation:

Electron orbitals in an atom (e.g., [tex]1s[/tex]) are denoted with:

A number, denoting the shell (principal energy level) of this orbital, andA letter, denoting the shape of this orbital ([tex]s[/tex], [tex]p[/tex], [tex]d[/tex], etc.)

There are two aspects to consider when finding the electron configuration of an atom:

The number of electrons that each type of orbitals could hold, andThe order in which the orbitals are filled.

The [tex]s[/tex] orbital in each shell could hold up to [tex]2 \times 1 = 2[/tex] electrons (one [tex]s\![/tex] orbital per shell, with up to two electrons.)

The [tex]p[/tex] orbitals in each shell could hold up to [tex]2 \times 3 = 6[/tex] electrons (three [tex]p\![/tex] orbitals per shell, with up to two electrons in each orbital.)

The [tex]d[/tex] orbitals in each main shell could hold up to [tex]2 \times 5 = 10[/tex] electrons (five [tex]d\![/tex] orbitals per shell, with up to two electrons in each orbital.)

Refer to the order in which the orbitals are filled (Aufbau principle.)

The first orbital to be filled would be [tex]1s[/tex] (the [tex]s[/tex] orbital of the first shell,) accommodating up to [tex]2[/tex] electrons.The second orbital to be filled would be [tex]2s[/tex] (the [tex]s[/tex] orbital of the second shell,) accommodating up to [tex]2[/tex] electrons.

All four electrons of Beryllium are thus assigned to the [tex]1s[/tex] and [tex]2s[/tex] orbitals. In a ground-state Beryllium atom, orbitals [tex]2p[/tex] and beyond would contain no electrons.

Notation:

Two electrons in the [tex]1s[/tex] orbital: [tex]1s^{2}[/tex] (the superscript denotes the number of electrons in this orbital (or group of orbitals).)Two electrons in the [tex]2s[/tex] orbital: [tex]2s^2[/tex].

Write the non-empty orbitals in the order by which they are filled:

[tex]1s^2\, 2s^2[/tex].

g Consider a pure sample of a radioactive isotope with a mass number of (46 A). If the sample has mass of (25.0 B) micrograms and the isotope has a half-life of (4.50 C)x106 years, determine the decay rate for the sample. Give your answer in decays/second and with 3 significant figures.

Answers

This question is incomplete, the complete question is;

g Consider a pure sample of a radioactive isotope with a mass number of (46 + A). If the sample has mass of (25.0 + B) micrograms and the isotope has a half-life of (4.50 + C)x10⁶ years,

determine the decay rate for the sample. Give your answer in decays/second and with 3 significant figures.

A = 1, B = 1, C = 11.

Answer:

the decay rate for the sample is 469,625.898 decay/s    

Explanation:

Given the data in the question;

[tex]T_{\frac{1}{2}[/tex] = ( 4.50 + C ) × 10⁶ years  

C = 11

[tex]T_{\frac{1}{2}[/tex] = ( 4.50 + 11 ) × 10⁶ years

[tex]T_{\frac{1}{2}[/tex] = 15.50 × 10⁶ years

[tex]T_{\frac{1}{2}[/tex] = 15.50 × 10⁶ × 365 × 24 × 60 × 60  

λ = 0.693 / [tex]T_{\frac{1}{2}[/tex]

so

λ = 0.693 / ( 15.50 × 10⁶ × 365 × 24 × 60 × 60  )

also

N = ( 25.0 + B )

B = 1

N = ( 25.0 + 1 )

N = 26 × 10⁻⁶

isotope with a mass number of ( 46.0 + A ) , A=1

= ( 46.0 + 1 ) = 47

N = 26 × 10⁻⁶( 1/47 )( 1 / 1.67 × 10⁻²⁷ ) =  3.31252 × 10²⁰  

R = λN

so

R = (0.693 / ( 15.50 × 10⁶ × 365 × 24 × 60 × 60  )) × (3.31252 × 10²⁰)

R = 1.41773 × 10⁻¹⁵ × (3.31252 × 10²⁰)

R = 469,625.898 decay/s    

Therefore, the decay rate for the sample is 469,625.898 decay/s    

What class of chemicals is responsible for ozone depletion?

Answers

Chlorofluorocarbons (CFCs) and other halogenated ozone-depleting substances (ODS) are mainly responsible for man-made chemical ozone depletion.


What is true about a car with constant velocity?

A. It has a zero acceleration
B.It has a changing direction
C.postive acceleration
D. Negative acceleration

Answers

A. It has a zero acceleration.

If something has a constant velocity, there is no acceleration!! Acceleration causes a change in a velocity and/or direction.

Answer:

Explanation:

c it’s see it

Which property increases as you move down a column in the periodic table?
A) atomic size
B) ionization energy
C) nonmetallic character
D) none of the above (all increase as you move down a column).

Answers

Answer:

A) atomic size

Explanation:

As mentioned, every step in the Fischer esterification mechanism is an equilibrium. As such, the reaction conditions are chosen in such a way to drive reaction to completion. a. For the reaction you have chosen, calculate the number of moles of carboxylic acid and the number of moles of alcohol given using the starting volumes given in the experiment

Answers

Answer:

Hello your question lacks some required information attached below is the missing information

answer :

number of moles

Acetic acid = 0.061199 mole

Alcohol = 0.027320 mole

Explanation:

The starting volumes :  2.5mL of either alcohol and 3.5mL of either acid

for the purpose of this solution I will take 2.5 mL of 1-butanol and 3.5 mL of acetic acid

mass of 1-Butanol = 2.5 mL * 0.81 g/mol = 2.025 g

∴ number of moles of 1-butanol = 2.025g / 74.12 g/mol = 0.027320 mole

mass of acetic acid = 3.5 mL * 1.05 g/mol = 3.675 g

∴ number of moles of Acetic acid = 3.675 g/ 60.05 g/mol = 0.061199 mole

Reaction equation

CH3-CH2-CH2-CH2-OH + CH3-COOH + H+ (cat) ↔ CH3-CH2-CH2-CH2-O-CO-CH3 + H2O

A voltaic cell is assembled by using two 30-mL beakers. In one beaker, Ag metal is used as the electrode with 10 mL of 1 M AgNO3. In the other beaker, Zn metal is used as the electrode with 10 mL of 1 M ZnSO4. The beakers are connected with a salt bridge and the measured cell potential, Eocell, is 1.50 V. The Zn electrode is negative (anode). Which reaction takes place at the Zn electrode

Answers

Answer:

Reaction that takes place at the Zn electrode is oxidation:

Zn ⇄  Zn²⁺  +  2e⁻

Explanation:

This excersise explains the structure of a typical battery, that is useful to study electrochemistry.

AgNO₃ → Ag⁺ + NO₃

ZnSO₄ → Zn²⁺  +  SO₄⁻²

Generally batteries contains 2 electrodes, where we have 2 conductive metallic. Batteries work to obtain electricity from a chemistry reaction which is always a redox type. One electrode releases electrons while the other catch them. Electrons travel from the anode to cathode, so in the anode, the e⁻ are released.

Reaction that takes place at the Zn electrode is oxidation:

Zn ⇄  Zn²⁺  +  2e⁻

Oxidation state is increased, electrons are free to go to cathode, where the other element decreases the oxidation state:

Ag⁺ + e⁻  ⇄ Ag

In the middle of the battery, the salt bridge (generally KCl) contributes the redox with more charges. Cl⁻ for the anode and K⁺ for the cathode.

Note that the same amount of electrons travel from anode to cathode, because in this example, Ag gained 1 mol and Zn released 2 moles.

The scheme for the battery is:

⁻  Zn(s) / Zn²⁺ (aq) //  Ag⁺ (aq) / Ag (s) ⁺

         1 M                               1 M                      

Where the first place represents the anode, // represents the salt bridge and then, the cathode.  Below, we write the molar concentration of each salt.

True or false solar power take power from wind and uses it to make electricity

Answers

The answer is false

C3H8(g) + 5O2(g) ⟶ 3CO2(g) + 4H2O(g) H = -2220 kJ If 865.9 g of H2O is produced during this combustion, how much heat is generated? Do not include the negative sign in your answer. Express the answer to the nearest whole number, or round to the nearest ones place. The molar mass of H2O is 18.02 g/mol.

Answers

Answer:

3 × 10⁴ kJ

Explanation:

Step 1: Write the balanced thermochemical equation

C₃H₈(g) + 5 O₂(g) ⟶ 3 CO₂(g) + 4 H₂O(g) ΔH = -2220 kJ

Step 2: Calculate the moles corresponding to 865.9 g of H₂O

The molar mass of H₂O is 18.02 g/mol.

865.9 g × 1 mol/18.02 g = 48.05 mol

Step 3: Calculate the heat produced when 48.05 moles of H₂O are produced

According to the thermochemical equation, 2220 kJ of heat are evolved when 4 moles of H₂O are produced.

48.05 mol × 2220 kJ/4 mol = 2.667 × 10⁴ kJ ≈ 3 × 10⁴ kJ

Question 6 of 10
What could make AG become negative at a given enthalpy and entropy?
A. Changing the temperature
B. Changing the concentrations
C. Changing the pressure
D. Changing the volume
SUBMIT

Answers

Answer:

A via A P E X

The entity that would make ΔG to become negative at a given enthalpy and entropy is Changing the temperature (Option A)

Gibbs free energy

ΔG = ΔH – TΔS

Where

ΔG is the Gibbs free energy ΔH is the enthalpy changeT is the temperature ΔS is the change in entropy

NOTE

ΔG = +ve (non spontaneous)

ΔG = 0 (equilibrium)

ΔG = –ve (spontaneous)

From the Gibbs free energy equation, we can see that the entities that makes us the equation are

Enthalpy, ΔHEntropy, ΔSTemperature, T

Thus, we can conclude that the correct answer to the question is: changing the temperature (Option A) since the equation has nothing to do with neither concentration, pressure nor volume

Learn more about Gibbs free energy:

https://brainly.com/question/9552459

#SPJ2

what is an optical property​

Answers

Answer:

The optical properties of a material define how it interacts with light. The optical properties of matter are studied in optical physics, a subfield of optics. Wiki.pedia

Explanation:

PDF on Unit operation 1 and 2​

Answers

https://mgdic.files.wordpress.com/2016/12/unit-operations.pdf this

#7 which of the following decreases the rate of solubility of solid molecules in a solution?

Answers

Answer:

7. Option D

Explanation:

Solubility increases with the increase in temperature of the solution. It is so because the increase in temperature leads to increase in kinetic energy which then breaks the solute particles held together by intermolecular attractions.

Hence, option D is correct

An electromagnet is the most powerful type of magnet there is. It is a magnet with a current running through it that can be turned on and off. Why might it be useful to be able to turn the electromagnet on and off?(1 point) 1

to not waste electricity

to control the strength of the magnet

to reduce wearing out of the magnet over time

to latch onto and let go of objects


What does electric current measure?(1 point) 2

how quickly electrical energy moves in a circuit

how frequently electrical energy moves in a circuit

how much electrical energy moves in a circuit

how well electrical energy moves in a circuit



How is a magnetic field produced?(1 point) 3

when an object has an electric charge

when electrons move through a circuit

when a current runs through a conductor

when an electromagnetic field interacts with a magnet


Which statement best describes how an electromagnetic motor works?(1 point) 4

Electrons are moved through a magnet, creating a circuit. That circuit interacts with a current, moving the conductor in the orientation of the field.

Electrons are moved through a circuit, creating a current. That current interacts with a magnet, moving the conductor in the orientation of the field.

Electrons are moved through a current, creating a circuit. That circuit interacts with a magnet, moving the conductor in the orientation of the field.

Electrons are moved through a magnet, creating a current. That current interacts with a circuit, moving the conductor in the orientation of the field.


Electromagnetism in Use Quick Check
5 of 5Items
Item 5
Use the image to answer the question.

A diagram shows a wire carrying a current in vertical direction. The magnetic field drawn using compass needles around the wire are concentric circles in a plane perpendicular to the direction of current.

What are the particles demonstrating in this image?

(1 point) 5

electric field

electromagnetic field

electromagnetic motor

magnetic field

Answers

Answer:

1. to latch onto and let go of eggs

2. how quickly electrical energy moves in a circuit

3.  when a current runs through a conductor

4. Electrons are moved through a circuit, creating a current. That current interacts with a magnet, moving the conductor in the orientation of the field.

5.  electromagnetic field

Which of the following is a conductor?
a) Glass
b) Wood
c) Gold
d) Oil

Answers

the answer is gold cause oil wood and glass are electrical insulators

Potassium iodide, KI, is used as an expectorant. How many grams are in 0.300 mole of potassium iodide?

Answers

Answer: 49.8 g

Explanation: molar mass M(KI) = 39.1+ 126.9 = 166 g/mol

Mass m= n·M= 0.3 mol· 166 g/mol

What lives in the arctic tundra biome? Choose all that apply.

Use this website to answer the question: https://thewildclassroom.com/biomes/artictundra-2/
Question 6 options:

caribou


reptiles


amphibians


lots of insects


muskox


reindeer

Answers

Answer: Animals found in the Arctic tundra include herbivorous mammals (lemmings, voles, caribou, arctic hares, and squirrels), carnivorous mammals (arctic foxes, wolves, and polar bears), fish (cod, flatfish, salmon, and trout), insects (mosquitoes, flies, moths, grasshoppers, and blackflies), and birds (ravens, snow buntings

The lives in Artic tundra biome is caribou.

What is arctic tundra biome?

Artic tundra biome is the northernmost biome, which covers the land of the arctics with the ice caps.

Climate of this Artic tundra biome is almost cold means the temperature in winter season of this region is about -34 degree celsius. In this region small animals like Norway lemmings as well as large animals like caribou are present which have high amount of fat to rescue from the cold.

Hence, option (a) is correct.

To know more about Artic tundra biome, visit the below link:
https://brainly.com/question/16056049


Someone please help me and thank you

Answers

Answer:

what grade is this?

I think it’s the first answer
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