When hydrogen is used in a fuel cell, the only waste product is/are __________

Answer:  [tex]3.45*10^{-7}[/tex]

Explanation:

we can use the equation Ka * Kb = Kw

Kw is the equilibrium constant and always equals to [tex]1*10^{-14}[/tex]

we plug the given numbers into the equation, [tex]Ka * (2.9*10^{-8} )=(1*10^{-14} )[/tex]

now we just solve for Ka, [tex]Ka=\frac{1*10^{-14} }{2.9*10^{-8} }[/tex]

which gives us the value, [tex]Ka=3.45*10^{-7}[/tex]

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The ka of the weak acid ha, whose conjugate base has kb 2. 9 × 10⁻⁸ is 3.45 × 10⁻⁷.

Ka value is the equilibrium constant found by the dissociation of acid.

By the equation

[tex]\rm ka \times kb = kw[/tex]

where kb = [tex]2.9 \times 10^-^8[/tex]

kw = [tex]1 \times 10^-^4[/tex]

Now, putting the values in the equation

[tex]1 \times 10^-^1^4 = ka \times 2.9 \times 10^-^8\\\\ka = \dfrac{1 \times 10^-^1^4}{2.9 \times 10^-^8} \\\\ka = 3.45 \times 10^-^7[/tex]

Thus, the ka of the weak acid ha, whose conjugate base has kb 2. 9 × 10⁻⁸ is 3.45 × 10⁻⁷.

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Answer:

6 moles of oxygen is required to burn 1 mole of C4H8 completely

Explanation:

reaction is C4H8 + (6)O2 ------ (4)CO2+ (4)H2O

Answer:

Morphine contains total 40 atom(s); 19 Hydrogen atom(s), 17 Carbon atom(s), 1 Nitrogen atom(s) and 3 Oxygen atom(s).

Explanation:

Answer:

Because X-rays have wavelengths similar to the size of atoms

X rays are used to probe the crystal structure of a material because this have same wavelength as atoms of crystal have.

X rays are the type of electromagnetic radiations and it is produced when the fast moving electron collide with the target anode and sudden deceleration takes place.

X rays have the high energy so that it easily penetrate in any crystal molecule as they also have same wavelength as atoms of the crystals have.

Hence due to high energy and same wavelength was of atoms of crystal it is used to probe the crystal.

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Answer:

I have no clue this qestion is kinda stumping but it a really good question it got me thinking but i don't know if there is a right answer

Explanation:

I don't know

The solute in the scenario where a chemist adds 36.0 g of sodium chloride to 200 g of water at STP and all of the sodium chloride is sodium chloride.

A solute is a substance that forms a solution with another substance called solvent in a process called solubility.

According to this question, a chemist adds 36.0 g of sodium chloride to 200 g of water at STP and all of the sodium chloride dissolves in the water.

This shows that the sodium chloride is the solute added to the water (solvent).

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The amount of heat transferred in and out of the system is measured by calorimetry. The thermometer in the calorimeter is used to measure the temperature.

The thermometer (A) is a device used to measure the final and the initial temperature of the water or any other liquid in a system. A metal vessel is a place where the reaction mixture is present.

In-vessel (B), water, and metal are placed before the beginning of the experiment. The styrofoam cup or the outer metal vessel (C) insulates the instrument, from regulating the heat transformation.

Therefore, part A measures the temperature of the reaction mixture.

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Answer:

1.4 moles/ 2.0 L= 0.7 M

Explanation: Molarity= moles of solute/ Liters of solution

therefore just plug the numbers in and you'll find the molarity to equal. 0.7

Answer:

I believe is the correct answer

Explanation:

NaCl made,2(NaCl)or2NaCl,Na2Cl,NaCl2 all represent compounds

Answer:

The independent variable is the calculator

The dependent variable is the speed of solving the problem.

The constant variable is the same set of problems that were assigned to two groups of students.  

The dependent variable is the one that is being tested by experimentation. The dependent variable depends on the independent variable.  

The independent variable can b changed by the experimenter whereas the constant variable remains unchanged throughout the experiment.  

Answer:

Controlled Variable: The same math problems

Dependent Variable: The amount of time taken to answer

Independent Variable: One group using calculators and the other group not using calculators.

Explanation:

The dependent variable is the variable being tested and the independent variable is what is being changed. The controlled is what is staying the same.

Given the following equation; Cu + 2AgNO3 = Cu(NO3)2 + 2Ag, 48.97 grams of Cu are needed to react with 262g of AgNO3.

The mass of a substance can be calculated using the following steps:

Cu + 2AgNO3 = Cu(NO3)2 + 2Ag

1 mole of Cu react with 2 moles of AgNO3

moles of AgNO3 = 262g/169.87g/mol = 1.54mol

1.54 moles of AgNO3 will react with 0.77 moles of Cu.

mass of Cu = 0.77 × 63.5 = 48.97g

Therefore, given the following equation; Cu + 2AgNO3 = Cu(NO3)2 + 2Ag, 48.97 grams of Cu are needed to react with 262g of AgNO3.

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Answer:

Yes

Explanation:

The process of respiration and burning are similar in the following ways: Both respiration and burning require oxygen. Energy is released during both respiration and burning. The products produced (carbon dioxide and water) are the same for both respiration and burning.

Answer:

Yes

Both Respiration and Burning uses oxygen. Both Respiration and Burning produces energy. Both Respiration and Burning gives out carbon dioxide as the end product. The overall chemical reactions of both Respiration and Burning are the same.

Explanation:

Please mark me brainliest if correct

Answer:

determiner is a word that introduces a noun or provides information about the quantity of a noun.

Explanation:

The metal cans are recyclable. (determiner before the adjective describing a plural noun to specify which cans)

Metal cans are recyclable. (no determiner because it's optional for plural nouns and noun phrases)

Answer:

please give a photo I can't now to help u

Answer:

they have a crystalline structure is the correct answer <3

Explanation:

The pH at equivalence point depends on the nature of the acid-base titration, and can either be acidic, basic, or neutral.

The equivalence point in a titration is the point at which equal amount of acid and base have reacted with each other.

The pH at equivalence point depends on the nature of the acids and bases being titrated.

pH at equivalence point will be:

Therefore, the pH at equivalence point depends on the nature of the acid-base titration.

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Answer:

any of the distinct types of material of which animals or plants are made, consisting of specialized cells and their products

Explanation:

Does this help you?

No

Answer:

diseases where microbes are the immediate cause are called infectious diseases. Infectious diseases are disorders caused by organisms — such as bacteria, viruses, fungi or parasites. Many organisms live in and on our bodies. They're normally harmless or even helpful.

Some possible public policies aimed at reducing the amount of carbon dioxide in the air is that companies should make use of new emissions technology to avoid air pollution.

What is air pollution?Air pollution is the release of substance that are dangerous or harmful to human health into the environment.

Excessive release of carbon dioxide into the atmosphere causes pollution and deplete our ozone layer.

One of the policy government have out in check is that all companies should purchase or make use of new emissions technology to avoid polluting the environment and causing harm to human health.

Therefore, some possible public policies aimed at reducing the amount of carbon dioxide in the air is that companies should make use of new emissions technology to avoid air pollution.

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Many policies are established to control air pollution like Tradable Permit System, Corrective Tax, Command-and-Control Policy, and Corrective Subsidy.

A corrective subsidy is a policy that encourages people to plant trees. Command-and-Control Policy or the regulation policy limits the emission of the particles that affect and harms the air and mandates the use of emissions-reducing technology.

Corrective Tax policy discourages negative effect behavior and imposes Pigovian tax that helps in achieving optimal pollutants. Tradable Permit System allows the figuring of the individual pollution emission.

Therefore, public policies are aimed to reduce air pollution through various means.

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Answer:

Amphiprotic

Explanation:

Answer:

advantages:

. The error due to weighing the solute can be minimised by using concentrated stock solution that requires large quantities of solute. 2. We can prepare working standards of different concentrations by diluting the stock solution which is more efficient since consistency is maintained

3. Some of the concentrated solutions are more stable and are less likely to support microbial growth than working standards used in the experiments.

Here is a Answer to your question:

Air pollution is caused by solid and liquid particles and certain gases that are suspended in the air. These particles and gases can come from car and truck exhaust, factories, dust, pollen, mold spores, volcanoes and wildfires. The solid and liquid particles suspended in our air are called aerosols.

Here are the 8 causes of air pollution?

1: The Burning of Fossil Fuels

2: Industrial Emission

3: Indoor Air Pollution

4: Wildfires

5: Microbial Decaying Process

6: Transportation

7: Open Burning of Garbage Waste

8: Construction and Demolition

I am sorry if this was not helpful

Hope this was helpful

Answer:

D

Explanation:

If the deer leave the forest then they are avoiding compotation

Answer:

Velocity

Explanation:

The rate of change of displacement is velocity.

Answer:

Velocity

Explanation:

The rate of change of displacement with time is called velocity.

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Answer:

Meteorites are consensually considered to be involved in the origin of life on this Planet for several functions and at different levels: (i) as providers of impact energy during their passage through the atmosphere; (ii) as agents of geodynamics, intended both as starters of the Earth’s tectonics and as activators of local hydrothermal systems upon their fall; (iii) as sources of organic materials, at varying levels of limited complexity; and (iv) as catalysts.

Explanation:

Answer:

[tex]\huge\boxed{\sf n = 7.36 \ mol}[/tex]

Explanation:

Given Data:

Volume = v = 42.19 L

Pressure = P = 428.792 kPa = 4.23 atm

Temperature = 27.871 °C + 273 = 300.871 K

R = the gas constant = 0.08206 L atm K⁻¹mol⁻¹

Required:

No. of moles = n = ?

Formula:

nRT = Pv

Solution:

Rearranging formula

[tex]\displaystyle n = \frac{Pv}{RT} \\\\n = \frac{(4.23)(42.19)}{(0.08206)(300.871)} \\\\n = \frac{181.467}{24.69} \\\\n = 7.36 \ mol\\\\\rule[225]{225}{2}[/tex]

The extra conversion of concentration of reactant and product should be zero in order to attaining equlibrium state.

Chemical equilibrium refers to the state in which both the reactants and products are present in equal concentrations or amount. In equlibrium, same amount of reactant is converted into product and product into reactant.

So we can conclude that the extra conversion of concentration of reactant and product should be zero in order to attaining equlibrium state.

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Answer: I learned that almost every technology has radio waves that spread out from their sources.

Explanation:

Elecetronegativity will affect the replacement reactions as it attracts the bonded electrons towards itself.

Replacement reactions are those reactions in which replacement of any one element from any compound is done by any other element.

Electronegativity is the attracting power of any element to hold the bonded electron towards itself so that they will bear a partial negative charge on itself. If in any reaction replacement of anion is required and any compound have more electronegative element which bounded the bonded electron strictly and will not allow the formation of anion then it affects the activity of the reaction.

Hence electronegativity affect the replacement reactions.

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Answer: bulbs

Explanation: Daffodils and tulips are examples of bulbs.

Answer: Bulbs

Explanation: When you plant daffodils or tulips, you will see that the "seeds" are onion-like. Onions are bulbs, and so are daffodils and tulips.