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What is the most common isotope for element X

Answer:

The frequency of a wave that has a wavelength of 28 m is 1.07*10⁷ Hz.

Explanation:

Wavelength is the minimum distance between two successive points on the wave that are in the same state of vibration. It is expressed in units of length (m).

Frequency is the number of vibrations that occur in a unit of time. Its unit is s⁻¹ or hertz (Hz).

The propagation speed is the speed with which the wave propagates in the medium, that is, it is the magnitude that measures the speed at which the wave's disturbance propagates along its displacement. Relate the wavelength (λ) and the frequency (f) inversely proportional using the following equation:

v = f * λ.

Being:

Replacing:

2.998*10⁸ m/s= f* 28 m

Solving:

[tex]f=\frac{2.998*10^{8}m/s }{28m}[/tex]

f= 1.07*10⁷ Hz

The frequency of a wave that has a wavelength of 28 m is 1.07*10⁷ Hz.

Answer:

1. 0.125 mole

2. 42.5 g

3. 0.61 mole

Explanation:

1. Determination of the number of mole of NaOH.

Mass of NaOH = 5 g

Molar mass of NaOH = 23 + 16 + 1

= 40 g/mol

Mole of NaOH =?

Mole = mass /molar mass

Mole of NaOH = 5/40

Mole NaOH = 0.125 mole

2. Determination of the mass of NH₃.

Mole of NH₃ = 2.5 moles

Molar mass of NH₃ = 14 + (3×1)

= 14 + 3

= 17 g/mol

Mass of NH₃ =?

Mass = mole × molar mass

Mass of NH₃ = 2.5 × 17

Mass of NH₃ = 42.5 g

3. Determination of the number of mole of Ca(NO₃)₂.

Mass of Ca(NO₃)₂ = 100 g

Molar mass of Ca(NO₃)₂ = 40 + 2[14 + (3×16)]

= 40 + 2[14 + 48]

= 40 + 2[62]

= 40 + 124

= 164 g/mol

Mole of Ca(NO₃)₂ =?

Mole = mass /molar mass

Mole of Ca(NO₃)₂ = 100 / 164

Mole of Ca(NO₃)₂ = 0.61 mole

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.

Explanation:

2C +O2 = 2CO

this will be the answer

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:

D Period 1, Group 18

Explanation:

it's helium

it's top right corner of the periodic table

Answer:

Im pretty sure its true

Explanation:

Answer:

answer is true .

Explanation:

this may help you

i know the answer is a theory

Answer: The heat energy produced is 53831.25KJ

Explanation:

METHANE is the main component of natural gas. It can undergo combustion reaction in air with a bright blue flame to produce carbondioxide and water. The heat of reaction (enthalpy) is negative because heat is absorbed during the chemical reaction. To calculate the heat energy produced by the combustion of one kilogram (1 kg) of methane the following steps are taken:

Molecular mass of methane =16 gm/mol.

So moles of 1 kg methane =

Given mass of methane ÷ molecular weight of methane

But the given mass = 1kg = 1000g

Therefore,

moles of 1000g methane = 1000÷16

= 62.5 moles

Hence, energy evolved = (moles of methane) × (heat of combustion)

Therefore,

heat energy produced= 62.5 × (-861.3kj)

= -53831.25kj

​

The heat energy produced by the combustion of one kilogram of methane is –53831.25 KJ

We'll begin by calculating the number of mole in 1 Kg of CH₄

Mass of CH₄ = 1 kg = 1000 g

Molar mass of CH₄ = 12 + (4×1) = 16 g/mol

Mole = mass /molar mass

Mole of CH₄ = 1000 / 16

CH₄ + 2O₂ —> CO₂ + 2H₂O ΔH = –861.3 KJ

From the balanced equation above,

1 mole of CH₄ reacted to produce –861.3 KJ.

Therefore,

62.5 moles of CH₄ will react to produce = 62.5 × –861.3 = –53831.25 KJ

Thus, –53831.25 KJ of heat energy is produced.

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Answer:

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

Explanation:

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!

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:

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:

(6 mol)·(-393.5 kJ/mol) + (6 mol)·(-285.83 kJ/mol) - (1 mol)·(-1,273.02 kJ/mol) + (6 mol)·(0 kJ/mol)

Explanation:

Question; From the given options, the chemical reaction in the question is presented as follows;

C₆H₁₂O₆(s) + 6O₂(g) → 6CO₂(g) + 6H₂O(l), given that we have;

[tex]\Delta \text H _f^{\circ}[/tex] for C₆H₁₂O₆ = -1,273.02 kJ/mol

[tex]\Delta \text H _f^{\circ}[/tex] for O₂(g) = 0 kJ/mol

[tex]\Delta \text H _f^{\circ}[/tex] for CO₂(g) = -393.5 kJ/mol

[tex]\Delta \text H _f^{\circ}[/tex] for H₂O(l) = -285.83 kJ/mol

The heat or enthalpy of a reaction,  is given as follows;

[tex]\Delta\text H_{rxn}^{\circ} = \sum \text n \cdot \Delta \text H _f^{\circ}(\text {products}) - \sum \text m \cdot \Delta \text H _f^{\circ}(\text {reactants} \text)[/tex]

Therefore, the equation which should be used to calculate [tex]\Delta\text H_{rxn}^{\circ}[/tex], is given as follows;

[tex]\sum \text n \cdot \Delta \text H _f^{\circ}(\text {products})[/tex] = (6 mol)·(-393.5 kJ/mol) + (6 mol)·(-285.83 kJ/mol)

[tex]\sum \text m \cdot \Delta \text H _f^{\circ}(\text {reactants} \text)[/tex] = (1 mol)·(-1,273.02 kJ/mol) + (6 mol)·(0 kJ/mol)

Therefore;

[tex]\Delta\text H_{rxn}^{\circ}[/tex] = (6 mol)·(-393.5 kJ/mol) + (6 mol)·(-285.83 kJ/mol) - (1 mol)·(-1,273.02 kJ/mol) + (6 mol)·(0 kJ/mol)

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.

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:

3. The mass of ethanol required is approximately 0.522869 g

The mass of ethanoic acid required is approximately 0.68156 g

4. The mass of iron (III) oxide required is approximately 285.952.189.095 tonnes

5. The mass of silver nitrate required is approximately 14.53 grams

6. The mass of copper oxide that would be needed is approximately 31.86 grams

7. a. The mass of the precipitate, Zn(OH)₂ formed is approximately 49.712 grams

b. The mass of the precipitate, Al(OH)₃ formed is approximately 13 grams

c. The mass of the precipitate, Mg(OH)₂, formed is approximately 14.579925 grams

Explanation:

3. The 1 mole of ethanol and 1 mole of ethanoic acid combines to form 1 mole of ethyl ethanoate

The number of moles of ethyl ethanoate in 1 gram of ethyl ethanoate, n = 1 g/(88.11 g/mol) = 1/88.11 moles

∴ The number of moles of ethanol = 1/88.11 moles

The number of moles of ethanoic acid = 1/88.11 moles

The mass of ethanol = (46.07 g/mol) × 1/88.11 moles = 0.522869 g

The mass of ethanoic acid in the reaction = 60.052 g/mol × 1/88.11 moles ≈ 0.68156 g

4. 1 mole of iron(III) oxide reacts with 1 mole of CO₂ to produce 1 mole of iron

The number of moles in 100 tonnes of iron= 100000000/55.845 = 1790670.60614 moles

The mass of iron (III) oxide required = 159.69 × 1790670.60614 = 285952189.095 g ≈ 285.952.189.095 tonnes

5. The number of moles of NaCl in 5 grams of NaCl = 5 g/58.44 g/mol = 0.0855578371 moles

The mass of silver nitrate required, m = 169.87 g/mol × 0.0855578371 moles ≈ 14.53 grams

6. The number of moles of CuSO₄·5H₂O in 100 g of CuSO₄·5H₂O = 100 g/(249.69 g/mol) ≈ 0.4005 moles

The mass of copper oxide required, m = 79.545 g/mol × 0.4005 moles ≈ 31.86 grams

7. a. The number of moles of NaOH in the reaction = 20 g/(39.997 g/mol) ≈ 0.5 moles

2 moles of NaOH produces 1 mole of Zn(OH)₂

0.5 moles of NaOH will produce 0.5 mole of Zn(OH)₂

The mass of 0.5 mole of Zn(OH)₂ = 0.5 mole × 99.424 g/mol = 49.712 grams

The mass of the precipitate, Zn(OH)₂ formed = 49.712 grams

b. 6 moles of NaOH produces 2 moles Al(OH)₃

20 g, or 0.5 mole of NaOH will produce (1/6) mole of Al(OH)₃

The mass of the precipitate, Al(OH)₃ formed, m = 78 g/mol×(1/6) moles = 13 grams

c. 2 moles of NaOH produces 1 mole of Mg(OH)₂, therefore;

20 g or 0.5 moles of NaOH formed (1/4) mole of Mg(OH)₂

The mass of the precipitate, Mg(OH)₂, formed, m = 58.3197 g/mol × (1/4) moles = 14.579925 grams

Answer:

Explanation:

i will show in details how 2 do the 1st Q n u can do the rest by following the way how it is done

3. given C^2H^5OH + CH^3CO^2H → CH^3CO^2C^2H^5 + H^2O

molar ratio of ethanol, ethanoic acid and ethyl ethanoate is 1 : 1 : 1

so mass = no. of moles * molecular mass

for same no. of moles, mass / molecular mass is the same

molecular mass of CH^3CO^2C^2H^5 = 12+1*3+12+16*2+12*2+5*1 = 88

molecular mass of C^2H^5OH = 12*2+1*5+16+1 = 46

molecular mass of CH^3CO^2H = 12+1*3+12+16*2+1 = 60

1 g of ethyl ethanoate = 1/88 mole

it requires 1/88*46 = 0.5227 g of ethanol; and

1/88*60 = 0.6818 g of ethanoic acid

to react together to form 1 g of ethyl ethanoate

Answer:

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thank you

Answer:

Unicellular organisms consist of only one cell and multicellular organisms consist of many cell.

Explanation:

Living things made up of a cell are called unicellular beings. They are very small and simple. In other words, unicellular organisms are those that are formed only by a single cell in which all the vital functions necessary for life are produced. For this reason, they are mostly microscopic organisms. Examples of unicellular organisms are viruses or bacteria.

Multicellular organisms are made up of a large number of cells. They present, therefore, a greater complexity than unicellular organisms in terms of the functions they develop. All current multicellular organisms come from a single cell, that is, they begin their life being unicellular. That is, they are formed from a zygote. Some examples of multicellular organisms are mammals, fungi, and mosses.

So, unicellular organisms consist of only one cell and multicellular organisms consist of many cell.

Answer:

Chloroplasts?

Explanation:

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:

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:

18.5g Na2CO3

Explanation:

Chromium (III) chloride, CrCl3, reacts with Na2CO3 as follows:

2CrCl3 + 3Na2CO3 → Cr2(CO3)3(s) + 6NaCl

Where 2 moles of CrCl3 react with 3 moles of Na2CO3 to produce 1 mole of Cr2(CO3)3 -The precipitate-

To solve this question we need to find the moles of CrCl3 added. With the chemical equation we can find the moles of Na2CO3 and its mass as follows:

Moles CrCl3:

520mL = 0.520L * (0.224mol/L) = 0.116 moles CrCl3

Moles Na2CO3:

0.116 moles CrCl3 * (3 mol Na2CO3 / 2mol CrCl3) = 0.175 moles Na2CO3

Mass Na2CO3 -Molar mass: 105.99g/mol-

0.175 moles Na2CO3 * (105.99g/mol) = 18.5g Na2CO3

Answer:

b, d, e

Explanation:

An atom is made up of electrons, protons and neutrons. Gold is an atom thus has the above particles.

Answer:

Answer to the following question is as follows.

Explanation:

Acid rain causes harm to houses and buildings by dissolving stone or corroding metal exposed to the elements. Acid rain can degrade calcium carbonate or calcium-based chemicals found in some of these products.

The acidic particles damage metal and accelerate the deterioration of paint and stone. They also make buildings and other structures, like as monuments, filthy.

Answer:

Percentage yield of O₂ = 73.4%

Explanation:

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

2KClO₃ —> 2KCl + 3O₂

Next, we shall determine the mass of KClO₃ that decomposed and the mass of O₂ produced from the balanced equation. This can be obtained as follow:

Molar mass of KClO₃ = 39 + 35.5 + (3×16)

= 39 + 35.5 + 48

= 122.5 g/mol

Mass of KClO₃ from the balanced equation = 2 × 122.5 = 245 g

Molar mass of O₂ = 2 × 16 = 32 g/mol

Mass of O₂ from the balanced equation = 3 × 32 = 96 g

SUMMARY:

From the balanced equation above,

245 g of KClO₃ decomposed to produce 96 g of O₂.

Next, we shall determine the theoretical yield of O₂. This can be obtained as follow:

From the balanced equation above,

245 g of KClO₃ decomposed to produce 96 g of O₂.

Therefore, 400 g 245 g of KClO₃ will decompose to produce

= (400 × 96)/245 = 156.7 g of O₂.

Thus, the theoretical yield of O₂ is 156.7 g

Finally, we shall determine the percentage yield of O₂. This can be obtained as follow:

Actual yield of O₂ = 115.0 g

Theoretical yield of O₂ = 156.7 g

Percentage yield of O₂ =?

Percentage yield = Actual yield /Theoretical × 100

Percentage yield = 115/156.7 × 100

Percentage yield = 11500/156.7

Percentage yield of O₂ = 73.4%

Answer:

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