Part A: The pH of a 0.0400 M solution of hydrocyanic acid is 5.71. Part B:The pH of a 0.170 M solution of aniline is 8.76.
Part A:
The first step is to write out the equation for the dissociation of hydrocyanic acid:
HCN + H₂O ⇌ H₃O⁺ + CN⁻
The acid dissociation constant, Ka, is given as 4.9 × 10⁻¹⁰. We can assume that the concentration of HCN that dissociates is x, and the concentrations of H₃O⁺ and CN⁻ that are formed are also x, since the mole ratio is 1:1:1.
Ka = [H₃O⁺][CN⁻]/[HCN]
Substituting the values:
4.9 × 10⁻¹⁰ = x²/0.0400
x = 1.97 × 10⁻⁶ M
The concentration of H₃O⁺ ions in the solution is also 1.97 × 10⁻⁶ M, since the mole ratio of H₃O⁺ to HCN is also 1:1.
pH = -log[H₃O⁺] = -log(1.97 × 10⁻⁶) = 5.71
Therefore, the pH of a 0.0400 M solution of hydrocyanic acid is 5.71.
Part B:
Aniline is a weak base, so we can write the equation for its dissociation as:
C₆H₅NH₂ + H₂O ⇌ C₆H₅NH₃⁺ + OH⁻
The base dissociation constant, Kb, is given as 4.3 × 10⁻¹⁰. We can assume that the concentration of aniline that dissociates is x, and the concentrations of C₆H₅NH₃⁺ and OH⁻ that are formed are also x, since the mole ratio is 1:1:1.
Kb = [C₆H₅NH₃⁺][OH⁻]/[C₆H₅NH₂]
Substituting the values:
4.3 × 10⁻¹⁰ = x²/0.170
x = 5.68 × 10⁻⁶ M
The concentration of OH⁻ ions in the solution is also 5.68 × 10⁻⁶ M, since the mole ratio of OH⁻ to C₆H₅NH₂ is 1:1.
pOH = -log[OH⁻] = -log(5.68 × 10⁻⁶) = 5.24
pH + pOH = 14, so:
pH = 14 - pOH = 8.76
Therefore, the pH of a 0.170 M solution of aniline is 8.76.
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PLEASE HELP ME 40 POINTS RIGHT ANSWERS ONLY :)
Answer:
Hi
Please mark brainliest ❣️
Thanks
Explanation:
Correct answer is D
Energy A
Look at this
Energy required to break bonds that is intermolecular forces
Pyridine, C5H5N, is a polar organic solvent. How many carbon atoms are in 7.05 moles of pyridine? 4.24 x 1024 4.24 x 10, 24 2.12 x 1024 2.12 x 10, 24 4.24 x 1023 4.24 x 10, 23 2.12 x 1025
Answer:
2.122×10^25atoms
Explanation:
number of moles=mass/molar mass
7.05moles= mass of pyridine/79
reacting mass of pyridine=556.95
C5H5N= (12×5)+(5)+(14)=79
C5=60
to find the mass of carbon in 556.95g of pyridine we take the stoichometric ratio
60[C5] -----> 79[C5H5N]
x[C5] --------> 556.95g[C5H5N]
cross multiply
x=(60×556.95)/79
x=423g of carbon
moles=mass/molar mass
moles of carbon=423/12
moles=35.25moles of carbon
moles=number of particles/Avogadro's constant
35.25=number of particles/6.02×10^23
number of particles=2.122×10^25atoms of carbon
The number of carbon atoms present in the 7.05 moles of pyridine is equal to 2.12 ×10²⁵. Therefore, option (D) is correct.
What is Avogadro's number?Avogadro’s number can be useful to express the number of particles in 1 mole of a chemical substance. Generally, these particles can be ions, atoms, molecules, electrons, or protons, according to the type of chemical reaction.
Avogadro’s constant is experimentally found approximately equal to 6.022 × 10²³ per mole.
Given, the number of moles of the Pyridine = 7.05 mol
The molar mass of the C₅H₅N = 79 g/mol
On molecule of pyridine has carbon atoms = 5
One mole of pyridine has carbon atoms = 5 × 6.022 × 10²³
Then 7.05 moles of pyridine have carbon atoms = 7.05 ×5 × 6.022 × 10²³
= 2.12 ×10²⁵ carbon atoms
Therefore, 2.12 ×10²⁵ carbons are present in 7.05 moles of pyridine.
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Explain which has a greater impact on the kinetic energy of an object - the
object's mass or the object's speed?
Answer:
it is the objects mass, I learned this last semester
The object's mass has a greater impact on the kinetic energy of an object as it is the mass the mass on which force is exerted and in which energy is stored to be transformed in to kinetic energy.
What is force?Force is defined as a cause which is capable of changing the motion of an object. It can cause an object which has mass to change it's velocity. It is also simply a push or a pull . It has both magnitude as well as direction.Hence, it is a vector quantity.
It has SI units of Newton and is represented by'F'.Newton's second law states that force which acts on an object is equal to momentum which changes with time. If mass of object is constant, acceleration is directly proportional to net force acting on an object.
The concepts which related to force are thrust and torque .Thrust increases the velocity of an object and torque produces change in rotational speed of an object.
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The main function of the kidney bladder and ureter is-?
Answer:
The urinary system's function is to filter blood and create urine as a waste by-product. The organs of the urinary system include the kidneys, renal pelvis, ureters, bladder and urethra.
Explanation:
a 5.0 g sample of a hydrate of bacl2 was heated, and only 4.3 g of the anhydrous salt remained. what percentage of water was in the hydrate?
The percentage of water in the hydrate is 14%.
To determine the percentage of water in a hydrate, you need to know the original mass of the hydrate and the mass of the anhydrous salt (the salt without water) that is left after heating.
In this case, the original hydrate had a mass of 5.0 grams and after heating, 4.3 grams of anhydrous salt remained. To find the percentage of water, you would divide the mass of the water lost (5.0g - 4.3g = 0.7g) by the original mass of the hydrate (5.0g) and multiply by 100%.
0.7g / 5.0 g × 100% = 14%
This the percentage of water in the hydrate is 14%.
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A 4.80g piece of magnesium displaces 2.76 mL of water when it is placed in a graduated cylinder. What is the density of magnesium?
Answer:
6
What do AIA, SAG, AFP and AMA all stand for? Select four options.
American Institute of Architects
American Society of Mechanical Engineers
American Medical Association
Screen Actors Guild
Association for Finance Professionals
Professional Colleges
36.512 ml of aqueous solution containing 0.111 moles of reactant a in a calorimeter at 25.0oc undergoes the following reaction: a(aq) --> b(aq). (the solution and the calorimeter are initially both at 25oc) when the reaction is complete, the temperature of the solution and the calorimeter is 46.84 oc. what is the enthalpy of the reaction in units of kj/mole of a? assume that the density of the solution is 1.000 g/ml, the specific heat of the solution is 4.186 j/goc, and the calorimeter has a heat capacity of 15.558 j/oc.
The enthalpy of the reaction is -58.7928 kJ/mol of A. Note that the negative sign indicates that the reaction is exothermic (heat is released).
To calculate the enthalpy of the reaction (ΔH) in units of kJ/mole of A, we can use the following equation; ΔH = -q/n
where q is the heat absorbed or released by the reaction, and n is the number of moles of reactant A.
First, we need to calculate the heat absorbed or released by the reaction (q). We can use the following equation to calculate q:
q = m × c × ΔT + C_cal × ΔT
where m is the mass of the solution, c is the specific heat of the solution, ΔT is the change in temperature (T_final - T_initial), and C_cal is the heat capacity of the calorimeter.
The mass of the solution can be calculated using the density of the solution;
mass = volume × density = 36.512 mL × 1.000 g/mL = 36.512 g
Substituting the given values, we get;
q = 36.512 g × 4.186 J/g°C × (46.84°C - 25.0°C) + 15.558 J/°C × (46.84°C - 25.0°C)
= 6524.1 J
Next, we need to calculate the number of moles of reactant A
n = 0.111 moles
Now we can calculate the enthalpy of the reaction:
ΔH = -q/n = -(6524.1 J)/(0.111 moles) = -58792.8 J/mol
Finally, we convert the result to kJ/mol
ΔH = -58.7928 kJ/mol
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CORE QUESTION: Cite some of the differences between the traditional fire-resistant material used in firefighters’ suits and FireArmor.
The traditional fire-resistant material used in firefighters’ suits are made of asbestos fabric, Nomex, and Melamine while fire armor is made of leather, fabric, or mixed layers of both, reinforced by quilting or felt, interwoven rings of iron or steel, metal, horn, wood, plastic, or some other similar tough and resistant materials.
What is firefighters’ suits?This refers to an outfit made to protect a firefighter or volcanologist from extremely high temperatures. firefighters’ suits are made of the following materials Nomex an aramid fibre, Melamine a thermosetting plastic, asbestos fabric, Kevlar, and Indura, PBI, Proban etc.
What is FireArmor?This refers to an outfit that creates a shield around the user's body against fire.
Three type of Fire armour
Armour:This is made of leather, fabric, or mixed layers of both, sometimes reinforced by quilting or felt. Mail: This is made of interwoven rings of iron or steel. Rigid armour:This is made of metal, horn, wood, plastic, or some other similar tough and resistant materials.Learn more about firefighters’ suits on
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7.8 L =mLDimensional AnalysisRatio:ProportionFormula MethodmLХLx mL=IImL11
answer and explanation
1 L = 1000 mL
and so to determine 7.8L we can o the calculation as follows
x mL = 1000 mL/ 1 L x 7.8 L/1 = 7800 mL/1 = 7800 mL
Help please help me!!!!!
Answer:
B. 460 NM
Explanation:
THAT THE ANSWER
. Photosynthesis and cellular respiration are two processes that help drive Earth's carbon cycle. Which f the following statements best describes one of these processes? Photosynthesis depends on the presence of carbon dioxide. b. Photosynthesis releases water as an end product. Respiration releases oxygen that is utilized by animals. d. Respiration depends on the presence of water in the atmosphere. C. 135 words 8:53 AM 12/1/2020 W
Answer:
Explanation:
a
Answer: photosynthesis releases water as an end product
Explanation:
You heat 100 mL of water and 1000 mL of water using 40,000 joules of energy. What would be the outcome of this experiment? *
A. The 100 mL of water would be a higher temperature than the 1,000 mL of water.
B. The 100 mL of water would be a lower temperature than the 1,000 mL of water.
C. They would both be the same temperature.
D. There is not enough information
Answer:
A. The 100 mL of water would be a higher temperature than the 1,000 mL of water.
Explanation:
Since the volume of water affects temperature, when the volume increases this results in a lower temperature. This means that the water with the smaller volume will have a higher temperature.
two types of fine chemical
Answer:
Flavors and fragrances
eugenol can also be isolated from cloves using extraction with co2. a. true b. false
b. false
Eugenol is typically extracted from cloves using methods such as steam distillation or solvent extraction, but not with CO2 extraction. CO2 extraction is a technique commonly used to extract essential oils from various plant materials, but it is not the preferred method for isolating eugenol from cloves.
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How are advancements in chemistry related to technology?
PLEASE BE ACCURATE! Thank you very much!:)
Advancements in chemistry have played a critical role in advancing technology in a number of ways such as ;
PharmaceuticalsEnergyNanotechnologyWhat is the relationship of advancements in chemistry to technology?Overall, advancements in chemistry are essential for developing new technologies and improving existing ones. By understanding the fundamental properties of materials and substances, chemists can create new materials with unique properties and develop new technologies that can improve our lives.
In term of Energy, Chemistry is crucial for developing new forms of energy, including renewable energy sources like solar, wind, and biofuels. Chemistry also plays a vital role in energy storage, such as the development of high-capacity batteries and fuel cells.
In term of Pharmaceuticals, Chemistry is essential for developing new drugs and improving existing ones. For example, the development of new cancer drugs has revolutionized cancer treatment, and new antibiotics have been developed to combat drug-resistant bacteria.
In term of Nanotechnology, Chemistry is critical for the development of nanotechnology, which involves working with materials at the nanoscale. Nanotechnology has many potential applications, including in electronics, medicine, and energy storage.
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PLS HELP ASAP!!!!!! WILL GIVE BRAINLIEST!!!!!!!!!!
Write a summary paragraph for each part discussing this experiment and the results. Use the following questions and topics to help guide the content of your paragraph. Part 1 What was your hypothesis? According to your data, do you think your hypothesis was correct? (Be sure to refer to your data when answering this question.) Summarize any difficulties or problems you had in performing the experiment that might have affected the results. Describe how you might change the procedure to avoid these problems. Be sure to submit your data along with your paragraph. Part 2 What effect did the temperature have on the viscosity of the honey? (Be sure to refer to your data when answering this question.) Give at least two practical examples where knowledge of viscosity is important.
Answer:
Explanation:
Dang which subject is this history or science
HELP ILL GIVE 100 POINTS
If you put a piece of zinc into a solution of copper (I) sulfate and allow the single replacement reaction to go to completion, how will you know which of the reactants is the limiting reactant? Write the balanced equation, including the states of matter of the reactants and products, to help support your answer.
How many grams are in 7.50 moles of Hg?
Answer:
0.03738970038
Explanation:
7.50 x 0.0049852933845157 = 0.03738970038
Why would Pluto be colder than all of the other planets?
Answer:
Pluto is farthest from the sun and hence it receives extremely low energy of sun. The surface temperature of Pluto is about -240 !!!
If Half- life of an isotope is 30 days and it was assumed that
the person ate 100 Bq of isotope. Using the GI track model
information, calculate the number of transformations in
Stomach
If Half- life of an isotope is 30 days and it was assumed that the person ate 100 Bq of isotope, there are 50 transformations in the stomach.
The radioactive decay of a sample of an isotope can be characterized by the half-life of that isotope. When a radioisotope undergoes decay, its nucleus becomes unstable, and it emits particles or energy to become more stable. The half-life of an isotope is the time it takes for half of the original sample to decay. The question states that the half-life of an isotope is 30 days, and the person ingested 100 Bq of isotope. It also says to calculate the number of transformations in the stomach using GI track model information .
Since the isotope has a half-life of 30 days, we can use the following formula to find the number of transformations in the stomach:` N = N₀ (1/2)^(t/T₁/₂)`where: N₀ = initial number of nuclei N = final number of nuclei (after time t)T₁/₂ = half-life of the isotope The isotope has a half-life of 30 days, so T₁/₂ = 30 days. The question doesn't specify how long the person has had the isotope in their stomach, so we'll assume it's been there for one half-life, or 30 days. Therefore, t = 30 days.
Substituting into the formula:` N = 100 (1/2)^(30/30)`Simplifying:` N = 100 (1/2)^1`Evaluating:`N = 50`So after 30 days in the stomach, the person would have 50 Bq of the isotope left. Therefore, the number of transformations in the stomach is the difference between the initial number of transformations (100 Bq) and the final number of transformations (50 Bq):`Number of transformations in stomach = 100 - 50 = 50 transformations. Therefore, there are 50 transformations in the stomach.
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What happens to unstable nuclei? (Select all that apply.)
1. They decay into more stable nuclei.
2. Their mass decreases by 50% with each half-life.
3. They emit radiation.
4. They combine to form more stable nuclei.
The activities which occurs in unstable nucleus from the above choices are:
They decay into more stable nuclei.Their mass decreases by 50% with each half-life.They emit radiation.They combine to form more stable nuclei.The correct answer choices are all 1, 2, 3 and 4.
How unstable nucleus decay into more stable nucleusIt follows that unstable nucleus usually, frequently and most of the time emit radiation and when this occur, it results to decay of substances.
From the task given above, it is crystal clear that that all the choices given above are happenings which occur when an unstable nucleus undergoes radioactive decay.
So therefore, we can now confirm that the nucleus of unstable atoms does decay into more stable nucleus.
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Which of the following best describes the characteristic of a mixture?
The characteristic of a Mixture is two or more elements coming together such as water (H2O) & Sugar Particles. If you mix these together you get a Mixture.
Explain how we know that charge is conserved in this
reaction: Li+ CI → Lici
Answer:
Charge is conserved due to the groups in which Lithium and Chlorine are located in the periodic table of the elements.
Explanation:
In the reaction \(Li + Cl - > LiCl\), we can examine the groups in which Li and Cl are found in the periodic table of the elements. Lithium appears in Group 1A, or the alkali metals group, indicating that it carries a charge of +1. Chlorine appears in Group 7A, or the halogen group, indicating that it carries a charge of -1. Because LiCl's constituent elements carry the same charges as previously mentioned, LiCl will have an overall charge of 0.
The chemical equation can then be rewritten as \(Li^{+} + Cl^{-} - > LiCl\), which, if looking at the individual charges of Li and Cl in lithium chloride, becomes \(Li^{+} + Cl^{-} - > Li^{+}Cl^{-}\). Adding the charges on the reactant and product sides of this chemical equation gives us zero in both locations, meaning that we have a charge of 0 on the reactant side and a charge of 0 on the product side. This indicates that charge is conserved in this reaction.
Another way to look at this is expressed in the valence electrons of Li and Cl. Li has an electron configuration of \(1s^{2}2s^{1}\), where the n = 2 electron shell has one of eight total electrons needed to fill the valence shell. This means that Li will easily lose one electron in order to have an electron configuration where the n = 1 electron shell is full, \(1s^{2}\), and become the \(Li^{+}\) ion. Similarly, Cl has an electron configuration of \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{5}\) (or \([Ne]3s^{2}3p^{5}\)), meaning that the n = 3 electron shell is one electron away from becoming complete. Cl will easily gain one electron to have the electron configuration \([Ne]3s^{2}3p^{6}\) (or \([Ar]\)) in order to have an electron configuration where the n = 3 electron shell is full, \(3s^{2}3p^{6}\), and become the \(Cl^{-}\) ion. Thus, when Li and Cl bond, Li will lose the electron \([1, 0, 0, +\frac{1}{2}]\) and transfer it to Cl, where it will become the electron \([3, 1, 1, -\frac{1}{2}]\), thus conserving charge, as there is an equal total number of electrons before and after the reaction.
PLEASE I REALLY NEED ANSWER REAL QUICK
1. 800g of solution of NaCl has 5% of the percent by mass. Find mass of water is required?
a. 780g
b. 760g
c. 740g
d. 720g
e. Other.. and give solution.
Answer:
b. 760 g
Explanation:
The mass of the solution = 800 g
5% of NaCl by mass of the solution can be determined as follows;
5% of 800 = \(\frac{5}{100}\) × 800
= 5 × 8
= 40 g
The mass of NaCl in the solution is 40 g.
The mass of water = mass of solution - mass of NaCl
= 800 - 40
= 760 g
Therefore, the mass of water required is 760 g.
What is the measure of the indicated angle? 37∘ 53∘ 180∘ 127∘
Answer:
53∘
plz mark me as brainliest.
Recall that matter cannot move without energy. What is the energy source that moves the red dye? What is the energy source that moves the blue dye? 2 points
The heat from the water in the cup beneath it provided the energy that moved both the red and blue dye. The dye particles move faster as the temperature rises.
What is heat convection?Heat convection is a mode of heat transfer that occurs through the motion of fluids (liquids or gases). When fluids are heated, their molecules move faster, which makes them less dense and causes them to rise.
This creates a current of warm fluid that transfers heat to cooler regions of the fluid or to other objects in contact with it. Convection is responsible for many everyday phenomena, such as the circulation of air currents in a room or the movement of water in a boiling pot.
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How many orbitals correspond to each of the following designations?
(a) 3p;
(b) 4p;
(c) 4p
;
(d) 6d;
(e) 5d;
(f) 5f;
(g) n = 5;
(h) 7s.
(a) The designation 3p corresponds to one orbital.
(b) The designation 4p corresponds to three orbitals.
(c) The designation 4p corresponds to three orbitals.
(d) The designation 6d corresponds to five orbitals.
(e) The designation 5d corresponds to five orbitals.
(f) The designation 5f corresponds to seven orbitals.
(g) The designation n = 5 corresponds to 50 orbitals.
(h) The designation 7s corresponds to one orbital.
(a) The designation 3p corresponds to one orbital. In the p sublevel, there is a single set of three orbitals: px, py, and pz. The designation "3p" specifies that we are referring to the p orbital within the third energy level.
(b) The designation 4p corresponds to three orbitals. Similar to (a), the p sublevel has three orbitals: 4px, 4py, and 4pz. The "4p" designation indicates that we are referring to the p orbitals within the fourth energy level.
(c) It seems that there was a repetition of the 4p designation in your list. So, again, the 4p designation corresponds to three orbitals.
(d) The designation 6d corresponds to five orbitals. The d sublevel has five orbitals: 6dx^2-y^2, 6dz^2, 6dxy, 6dxz, and 6dyz. The "6d" designation indicates that we are referring to the d orbitals within the sixth energy level.
(e) The designation 5d corresponds to five orbitals. Similarly to (d), the d sublevel has five orbitals: 5dx^2-y^2, 5dz^2, 5dxy, 5dxz, and 5dyz.
(f) The designation 5f corresponds to seven orbitals. The f sublevel has seven orbitals: 5fz^3, 5fxz^2, 5fyz^2, 5fxyz, 5fx(x^2-y^2), 5fy(x^2-y^2), and 5f(x^2-3y^2).
(g) The designation "n = 5" represents all orbitals within the fifth energy level. The number of orbitals in a given energy level is determined by the formula 2n^2, where n is the principal quantum number. Therefore, for n = 5, there are 2 * 5^2 = 50 orbitals.
(h) The designation 7s corresponds to one orbital. The s sublevel contains a single orbital: 7s. The "7s" designation indicates that we are referring to the s orbital within the seventh energy level.
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3RD TIME TRYING CHEMISTRY QUESTION, PLEASE HELP
I've tried this question already but I didn't get the full answer. If you could help with all of them, that would be great <3
If Reaction B was at equilibrium and then was heated ______ CH3OH would be present after the reaction adjusts to the new temperature.
- more
- less
- the same amount of
If Reaction B was at equilibrium and then H2 was added, _____ CH3OH would be present after the reaction adjusts.
- more
- less
- the same amount of
If Reaction B was at equilibrium and then H2 was added, _____ CO would be present after the reaction adjusts.
- more
- less
- the same amount of
The effect of change of pressure, concentration and temperature on the state of equilibrium can be predicted with the help of Le Chatelier's principle.
What is Le Chatelier's principle?If a system in equilibrium is subjected to a change in concentration, pressure or temperature, the equilibrium shifts in the direction that tends to reduce the effect of the change.
According to Le Chatelier's principle, the increase of temperature will shift the equilibrium in the direction of endothermic reaction. Here the forward reaction is exothermic, so more amount of CH₃OH will be produced.
If H₂ is added, more amount of CH₃OH will be produced and less amount of CO will be present.
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osmosis and diffusion
Answer:
Osmosis: Osmosis is the movement of solvent particles across a semipermeable membrane from a dilute solution into a concentrated solution. ... Diffusion: Diffusion is the movement of particles from an area of higher concentration to lower concentration. The overall effect is to equalize concentration throughout the medium.
Explanation:
Whether a hydrogen-based energy system is environmentally cleaner than a fossil fuel system depends on ________. the car driven governmental incentives for research the amount of fossil fuels that are invested in long-term storage the source of oxygen used for the process the source of energy used to produce the hydrogen
A hydrogen energy system is made up of hydrogen production, transportation, storage, utilization etc. Whether a hydrogen-based energy system is environmentally cleaner than a fossil fuel system depends on the source of energy used to produce the hydrogen.
Hydrogen fuel cells often makes electricity by using hydrogen and oxygen atoms. The hydrogen is said to reacts with oxygen across an electrochemical cell.Hydrogen is known to carry some amount of energy carrier and can also deliver or store a large amount of energy. Hydrogen is often used in fuel cells to generate electricity, or power and heat.
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