Methane is the main component of natural gas. Using the given reaction enthalpy, calculate the heat energy produced by the combustion of one kilogram of methane.

Answer:

1) The percentage of oxygen in dry air is _______

C. 21

2) The composition of the Earth’s earliest atmosphere was different to that of the present atmosphere. Which of these gases was present in large amounts in the Earth’s earliest atmosphere?

B. CARBON DIOXIDE

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Answer: The percentage of oxygen in dry air is .  21

Explanation:  Ammonia gases was present in large amounts  in the easth7s earliest atmosphere

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Answer:

I hope that's what u were lookong for :))

Explanation:

Answer:

The combination of ions most likely to produce a precipitate is a group of answer choices:

lead nitrate soluble in water

Mg2+ and C2H3O2-.

Fe3+ and OH-.

Li+ and PO43-.

Pb2+ and NO3-.

NH4+ and SO42-.

Explanation:

Among the given options,

magnesium acetate, lithium phosphate, lead nitrate, ammonium sulfate are soluble in water.

The only one which is insoluble in water is [tex]Fe^3+[/tex] and [tex]OH^-[/tex] combination.

[tex]Fe(OH)_3[/tex] is insoluble in water. It forms a precipitate.

Answer:

Swimming pool is an example of solution

Explanation:

It has water (solvent) and dissolve ion (solute)

Answer:

it is a solution

Explanation:

the combining of (water and Cl and other pool chemicals) make it a solution.

Explanation:

2C +O2 = 2CO

this will be the answer

Answer:

A chemical bond formed when two atoms share two pairs of electrons is a double bond; it is best described as a covalent bond.

Explanation:

A chemical bond in which two pairs of electrons are shared has to be defined as covalent since ionic bonds don't involve electron sharing. They consist only of electrostatic attraction between ions.

Elements in the same family have the same number of protons. This  statement is not true about the periodic table. Therefore, option A is correct.

The chemical elements are arranged in rows and columns in the periodic table, sometimes referred to as the periodic table of the elements. It is frequently used in physics, chemistry, and other sciences and is frequently regarded as a symbol of chemistry.

The table can be used by scientists to anticipate chemical reactions, study trends in the periodic properties of certain elements, and speculate on the properties of yet-to-be-discovered elements. The elements are arranged in the contemporary periodic table according to their atomic numbers and periodic characteristics.

The periodic table has changed to represent more than 150 years of chemical and physics research and development.

Thus, option A is correct.

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Answer:

i think its C polymer hope it helps

Answer: The mass of ammonia is 124457.96 g which can be produced from reacting a 450 L sample of nitrogen gas at a temperature of 450 K and a pressure of 300 atm.

Explanation:

Given: Volume = 450 L

Temperature = 450 K

Pressure = 300 atm

The reaction equation is as follows.

[tex]N_{2} + 3H_{2} \rightarrow 2NH_{3}[/tex]

Here, 1 mole of nitrogen reacts to give 2 moles of ammonia.

From the given data, moles of nitrogen are calculated as follows.

PV = nRT

where,

P = pressure

V = volume

n = no. of moles

R = gas constant = 0.0821 L atm/mol K

T = temperature

Substitute the values into the above formula as follows.

[tex]PV = nRT\\300 atm \times 450 L = n \times 0.0821 L atm/mol K \times 450 K\\n = \frac{300 atm \times 450 L}{0.0821 L atm/mol K \times 450 K}\\= \frac{135000}{36.945}\\= 3654.08 mol[/tex]

For 3654.08 moles of nitrogen, the moles of ammonia produced is as follows.

[tex]2 \times 3654.08 mol\\= 7308.16 mol[/tex]

Therefore, mass of ammonia (molar mass = 17.03 g/mol) is calculated as follows.

[tex]Moles = \frac{mass}{molarmass}\\7308.16 mol = \frac{mass}{17.03 g/mol}\\mass = 124457.96 g[/tex]

Thus, we can conclude that the mass of ammonia is 124457.96 g which can be produced from reacting a 450 L sample of nitrogen gas at a temperature of 450 K and a pressure of 300 atm.

i know the answer is a theory

Answer:

D. Zn²⁺ + 2Ag → Zn + 2Ag⁺

Explanation:

On the reduction potential chart, we have that silver ion Ag⁺ is a stronger oxidizing agent than, zinc, Zn, which is a reducing reducing agent the compared to silver

Therefore, the redox reaction that will occur is that the zinc, Zn, will be oxidized to Zn²⁺ ion, while the silver, Ag²⁺ ion will be reduced to silver deposits Ag, therefore, the zinc will displace the silver in the solution containing silver and zinc ions because zinc is higher than silver in the reactivity series

The reduction potential Zn → Zn²⁺ + 2e⁻ = +0.76

The reduction potential for Ag⁺ + e⁻ → Ag = +0.8

Therefore, given that redox reactions are reversible, we get the following likely redux reaction;

Zn(s) + 2Ag⁺(aq) ⇄ 2Ag(s) + Zn²⁺(aq)

Therefore, from the given options;

Zn²⁺(aq) + 2Ag(s) → Zn(s) + 2Ag⁺(aq) is the reaction most likely to occur.

Answer:

b is your answer...........

Cu(s) + Ni(NO3)2(aq) ⇒Ni(s) + Cu(NO3)2(aq)

The answer is option B.

Electrochemical or hobby series when the electrodes (metals and non-metals) in touch with their ions are organized on the idea of the values of their preferred discount potentials or standard oxidation potentials, the resulting series is called the electrochemical.

The electrochemical series is built up by means of arranging various redox equilibria so as of their fashionable electrode potentials (redox potentials). The maximum poor E° values are placed at the pinnacle of the electrochemical series, and the maximum wonderful at the lowest.

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Answer:

Chemistry plays an important and useful role towards the development and growth of a number of industries. This includes industries like glass, cement, paper, textile, leather, dye etc. We also see huge applications of chemistry in industries like paints, pigments, petroleum, sugar, plastics, Pharmaceuticals.

Answer:

Im pretty sure its true

Explanation:

Answer:

answer is true .

Explanation:

this may help you

Answer:

b

Explanation:

Molecular formula of Decanoic Acid is  C₁₀H₂₀O₂ therefore Option A is the right answer.

Decanoic Acid is a C10 , straight chain , saturated fatty acid . Its general formula is C₁₀H₂₀O₂ .

In the first option we can see a straight chain , saturated fatty acid and the molecular formula is also same as decanoic acid .

In second option the molecular formula is C₉H₁₈O₂ which is not same as Decanoic Acid.

Hence option A is the right answer.

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Explanation:

If the iceberg is near the lake and the water molecules melt, then the molecules will slide down. The iceberg could be melting for many reasons - it can be purposely destroyed, the sun could be melting it, or it might naturally fall in. So, this is the answer to your question. Hope it helps!

Answer:

0.241 M

Explanation:

We'll begin by writing the balanced equation for the reaction. This is given below:

HBr + NaOH —> NaBr + H₂O

From the balanced equation above,

The mole ratio of acid, HBr (nₐ) = 1

The mole ratio of base, NaOH (n₆) = 1

Finally, we shall determine the concentration of the NaOH solution. This can be obtained as follow:

Volume of base, NaOH (V₆) = 20 mL

Volume of acid, HBr (Vₐ) = 24.1 mL

Concentration of acid, HBr (Cₐ) = 0.2 M

Concentration of base, NaOH (C₆) =?

CₐVₐ / C₆V₆ = nₐ/n₆

0.2 × 24.1 / C₆ × 20 = 1/1

4.82 / C₆ × 20 = 1

Cross multiply

C₆ × 20 = 4.82

Divide both side by 20

C₆ = 4.82 / 20

C₆ = 0.241 M

Therefore, the concentration of the NaOH solution is 0.241 M

Answer:

To determine the number of atoms of Boron that are present within 3.61 grams of Boron Trifluoride, it would be best to convert the grams to moles of the compound and then after that use the Avogadro's number to determine the number of molecules and then use the 1 to 3 ratio to determine the total number of Boron atoms.

Answer:

When gases in containers are heated, their molecules increase in average speed. This means that they exert a greater force when they collide with the container walls, and also collide with the walls more frequently. The gas is therefore under greater pressure when its temperature is higher.

Answer:

the process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a by-product.

Answer:

the process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a by-product.

Answer:

How many distinct monochlorinated products can result when methylcyclohexane is subjected to free radical chlorination under UV light.

Explanation:

Consider 1-methylcyclohexane:

Its structure is shown below:

It has primary [tex]1^o[/tex], secondary [tex]2^o[/tex]and tertiary [tex]3^o[/tex] carbons as shown in the image.

So, the following mono chlorinated product will be formed.

Answer:

Diatomic molecules contain two atoms that are chemically bonded. If the two atoms are identical, as in, for example, the oxygen molecule (O2), they compose a homonuclear diatomic molecule, while if the atoms are different, as in the carbon monoxide molecule (CO), they make up…

Explanation:

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Answer:

179.5 feet

Explanation:

54.718 m converted to 179.5 feet.