Percent composition. Please help meee :(

Answer:

Nine σ- and nine π

Explanation:

Nine σ- and nine π are there in the molecule of tetracyanoethylene.

The percentage of C in CO = 42.9%

Given

CO compound

Required

Percentage of C

Solution

Proust :

Compounds are formed from elements with the same Mass Comparison so that compounds have a fixed composition of elements

Ar of C = 12 g/mol

MW of CO = 28 g/mol

%C :

[tex]\tt =\dfrac{Ar~C}{MW~CO}\times 100\%\\\\=\dfrac{12}{28}\times 100\%\\\\=42.9\%[/tex]

answer to this question is = 42.9 %

Explanation:

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Find your answer in the explanation below.

Explanation:

PV = nRT is called the ideal gas equation and its a combination of 3 laws; Charles' law, Boyle's law and Avogadro's law.

According to Boyle's law, at constant temperature, the volume of a gas is inversely proportional to the pressure. i.e V = 1/P

From, Charles' law, we have that volume is directly proportional to the absolute temperature of the gas at constant pressure. i.e V = T

Avogadro's law finally states that equal volume of all gases at the same temperature and pressure contain the same number of molecules. i.e V = n

Combining the 3 Laws together i.e equating volume in all 3 laws, we have

V = nT/P,

V = constant nT/P

(constant = general gas constant = R)

V = RnT/P

by bringing P to the LHS, we have,

PV = nRT.

Q.E.D

Answer:

1. expanding

2. red, blue

3. red, spreading out

Explanation:

Answer:

[tex]K'=\frac{1}{16}[/tex]

Explanation:

Hello!

In this case, since the given reaction is:

[tex]A+ 2B \rightleftharpoons C+ \frac{5}{2} D[/tex]

Whereas the equilibrium constant is:

[tex]K=\frac{[C][D]^{5/2}}{[A][B]^2} =4.0[/tex]

However, the new target reaction reverses and doubles the initial reaction to obtain:

[tex]2C+5D \rightleftharpoons 2A+4B[/tex]

Whereas the equilibrium constant is:

[tex]K'=\frac{[A]^2[B]^4}{[C]^2[D]^5}[/tex]

Which suggest the following relationship between the equilibrium constants:

[tex]K'=\frac{1}{K^2}[/tex]

So we plug in to obtain:

[tex]K'=\frac{1}{4.0^2}\\\\K'=\frac{1}{16}[/tex]

Best regards!

Answer : 2 represent the coefficient.

Explanation :

As we know that:

The coefficients used in the chemical equations shows that the relative amounts of each substance present and this amount can represent either the relative number of molecules or number of moles.

If there is no coefficient then one (1) is assumed.

That means,

The coefficient tell us about that how many molecules or atoms present in the chemical equation.

By the stoichiometry we have to convert moles of a reactant to moles of a product.

The given formula is: [tex]2CH_4[/tex]

In this formula, 2 represent the coefficient and 4 represent the subscript and C and H represents the symbol of element.

Hence, 2 represent the coefficient.

Mass of sugar in the can : 21.3 g

Given

a 355ml can of soda

mass water = 355 g

density of soda = 1.06 g/ml

Required

mass of sugar

Solution

Mass of soda in the can :

= density x volume of the can

= 1.06 g/ml x 355 ml

= 376.3 g

Mass of sugar :

=mass of soda - mass of water

= 376.3 g - 355 g

= 21.3 g

Answer: 184 g of nitrogen dioxide that are produced from 4 moles of nitric oxide

Explanation:

The balanced chemical reaction is:

[tex]2NO(g)+O_2(g)\rightarrow 2NO_2(g)[/tex]  

According to stoichiometry :

2 moles of [tex]NO[/tex] produce = 2 moles of [tex]NO_2[/tex]

Thus 4 moles of [tex]NO[/tex] will require=[tex]\frac{2}{2}\times 4=4moles[/tex]  of [tex]NO_2[/tex]

Mass of [tex]NO_2=moles\times {\text {Molar mass}}=4moles\times 46g/mol=184g[/tex]

Thus 184 g of nitrogen dioxide that are produced from 4 moles of nitric oxide

Answer:

Mixtures are unlike chemical compounds, because: The substances in a mixture can be separated using physical methods such as filtration, freezing, and distillation.

Answer:

In increasing order:

Sr, Ca, Mg, Br

Answer:

pH of 7 is neutral

pH of 4 is weak acid

Explanation:

hope it helps you..

Answer:

False

Explanation:

Using less electricity will result in less fuel being burnt which will result in less fuel needing to be extracted from the earth which will reduce society's impact on earth.

Answer:

Calcium carbonate and citric acid.

Explanation:

Hello!

In this case, considering the text, we can notice that calcium carbonate combines with citric acid to produce the calcium citrate water and carbon dioxide as shown on the following equation:

[tex]3CaCO_3+2C_6H_8O_7\rightarrow Ca_3C_{12}H_{10}O_{14}+CO_2+H_2O[/tex]

Whereas the reactants, at the left side, are identified as calcium carbonate and citric acid.

Best regards!

Answer:

Science is the pursuit and application of knowledge and understanding of the natural and social world following a systematic methodology based on evidence. Experiment and/or observation as benchmarks for testing hypotheses

Explanation:

Explanation:

1. Latitude or distance from the equator – Temperatures drop the further an area is from the equator due to the curvature of the earth. In areas closer to the poles, sunlight has a larger area of atmosphere to pass through and the sun is at a lower angle in the sky.

Answer:

wave length=speed/frequency

=365/23

wave length=speed/frequency

=365/35000

Answer:

Element

Explanation:

Other things on that list like alloy and compound can be broken down, but elements cannot

Answer:

If it is made from solid silver then it is an element. If it is made from a silver alloy then it is a mixture. If it is a silver plated plate (i.e. a plate made from say, copper but with a thin layer of silver on top) then it is an element on top of an element.

Explanation:

I'm assuming you're talking about solid silver, so, i believe an element.

Answer:

C. 8 eV

Explanation:

In atoms, the energy of each level is quantised. That is one of the reasons why an electron can not exist between energy levels. Thus, when the electron absorbs energy of 8 ev, it get excited and jumps to energy level 2 which has the current value of energy of the electron.

Thus for the electron to move back to its initial energy level, it must emit the exact energy absorbed for its excitation. Therefore, the likely energy of the photon that will be emitted is 8 ev. This would make the electron to have energy that would make it to exist on energy level 1.

Answer:

62.07 %

Explanation:

Chemical Formula =  (CH3)2CO = C3H6O

Mass of C = 12 g/mol

Mass of H = 1 g/mol

Mass of O = 12 g/mol

Mass of  C3H6O = 3(12) + 6(1) + 16 = 58 g/mol

Total mass of C in Acetone = 12 * 3 = 36 g

Mass Percent of C =  Total mass of C / Mass of Acetone   *  100

Mass percent = 36 / 58    *  100

Mass percent = 62.07 %

Answer:

Your two answers are numbers of protons and electron and the second one is the atomic mass and weight.

Explanation:

God bless you are you got this

Answer:Number's 1, 2, and 4 are correct

Explanation:

Moles of Na theoretically extract : 10.256

Given

600 g of NaCl

Required

moles of Na

Solution

Na can be electrolyzed from NaCl(molten)

Na⁺ + e⁻⇒ Na

Cl⁻⇒1/2 Cl₂ + e⁻

Overall reaction :

NaCl⇒Na + 1/2 Cl₂ x2

2NaCl⇒2Na + Cl₂

mol of NaCl(MW=58.5 g/mol) :

= 600 g : 58.5 g/mol

= 10.256

From the equation, mol ratio of NaCl : Na = 2 : 1, so :

mol Na = mol NaCl = 10.256

Answer: 4.6 billion years ago

Explanation:

Answer:

4.6 billion years ago

hope this helps have a good day or night:)

Answer: The answer is D.gram

Explanation:

Explanation:

Examples of chemical changes include, rusting, fire, and overcooking. Nuclear changes occur when the nuclei of atoms are rearranged to form new atoms. Examples of nuclear changes include atomic fission, nuclear fusion, and the energy of sun and stars.

Answer:

12.5%

Explanation:

From the question given above, the following data were obtained:

Half-life (t½) = 2 h

Time (t) = 6 h

Percentage remaining =.?

Next we shall determine the number of half-lives that has elapse. This can be obtained as follow:

Half-life (t½) = 2 h

Time (t) = 6 h

Number of half-lives (n) =?

n = t / t½

n = 6/2

n = 3

Finally, we shall determine the percentage of original dosage remaining as follow:

Amount remaining (N) = Original amount (N₀) /2ⁿ

N = N₀ / 2ⁿ

Divide both side by N₀

N/N₀ = 1/2ⁿ

Input the value of n i.e 3

N/N₀ = 1/2³

N/N₀ = 1/8

N/N₀ = 0.125

Multiply by 100 to express in percent.

N/N₀ = 0.125 × 100

N/N₀ = 12.5%

Thus, percentage of original dosage remaining is 12.5%

B. 0.21 mol

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Step 1: Define

1.25 × 10²³ atoms Ca

Step 2: Identify Conversions

Avogadro's Number

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

0.207572 mol Ca ≈ 0.208 mol Ca

Answer:

N= mass/molar mass

complete the solve

Answer:

I would say the answer is 2

The formation of new mountains due to tectonic movements is reporting now whereas, some of  the olden mountains are worn down. Thus option 2 is correct.

Earth crests is made of tectonic plates of different sizes and shapes. These plates were not apart and was one in the earlier times of earth and no separate continents were there. When heat in the atmosphere made the magma hot and the hot fluid flow makes the plate moving.

The tectonic plate movement is different in different regions and its results be different. Some movements results in the formation of mountains mostly when the plates are moving each other and one plate rise the edge of others.

Some movement results in islands, folded mountains, volcanic mountains etc. These mountains may worn down over time and there is a possibility of formation of new mountains in regions where significant plate movement occurs.

To find more about  plate movement, refer the link bellow:

https://brainly.com/question/3970445

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Answer:

B

Explanation: