How many moles of aluminum are needed to react with 3.6 mol of FeO? 2Al(s) + 3FeO(s) → 3Fe(s) +Al₂O₃(s)

Arrange the following H atom electron transitions in order of decreasing wavelength of the photon absorbed or emitted:

Katyanochek1 [597]

The decreasing order of wavelengths of the photons emitted or absorbed by the H atom is : b → c → a → d

Rydberg's formula :

$\frac{1}{\lambda} = R_h (\frac{1}{n_1^2}-\frac{1}{n_2^2} )$ ,

where λ is the wavelength of the photon emitted or absorbed from an H atom electron transition from $n_1$ to $n_2$ and $R_h$ = 109677 is the Rydberg Constant. Here $n_1$ and $n_2$ represents the transitions.

(a) $n_1$ =2 to $n_2$ = infinity

$\frac{1}{\lambda} = 109677\times (\frac{1}{2^2}-\frac{1}{\infty^2} )$ = 109677/4 [since 1/infinity = 0] Therefore, $\lambda$ = 4 / 109677 = 0.00003647 m

(b) $n_1$ =4 to $n_2$ = 20

$\frac{1}{\lambda} = 109677\times (\frac{1}{4^2}-\frac{1}{20^2} )$ = 6580.62

Therefore, $\lambda$ = 1 / 6580.62 = 0.000152 m

(c) $n_1$ =3 to $n_2$ = 10

$\frac{1}{\lambda} = 109677\times (\frac{1}{3^2}-\frac{1}{10^2} )$ = 11089.56

Therefore, $\lambda$ = 1 / 11089.56 = 0.00009 m

(d) $n_1$ =2 to $n_2$ = 1

$\frac{1}{\lambda} = 109677\times (\frac{1}{2^2}-\frac{1}{1^2} )$ = - 82257.75

Therefore, $\lambda$ = 1 /82257.75 = - 0.0000121 m

[Even though there is a negative sign, the magnitude is only considered because the sign denotes that energy is emitted.]

So the decreasing order of wavelength of the photon absorbed or emitted is b → c → a → d.

Learn more about the Rydberg's formula athttps://brainly.com/question/14649374

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8 0

2 years ago

What does vinegar do to eggs

andre [41]

Eggshells are made primarily of calcium carbonate. The acid in vinegar softens the calcium of the eggshell. Adding a little vinegar to the water when boiling eggs is an old cook’s trick that makes them easier to peel.

A link to this experiment is below in the comment box

7 0

3 years ago

Researchers are investigating processes that happen during digestion. Which answer choice describes only a physical change durin

ElenaW [278]

The correct answer is B. Chewing in the mouth breaks food into small pieces.

Explanation:

In physical changes, substances do not change their chemical composition or properties but only physical features such as this. This occurs during the chewing because the action of chewing only makes food to be broken down in smaller pieces but does not change its identity, composition, or properties. This does not occur once the food is in contact with saliva, the acid in the stomach, etc. because in these cases, the food reacts with other substances and a chemical reaction occurs, which changes food's identity and composition.

8 0

3 years ago

4.1 moles of sodium carbonate to molecules of sodium carbonate.

docker41 [41]

<h3>Answer:</h3>

2.47 × 10^24 molecules

<h3>Explanation:</h3>

One mole of a compound contains molecules equivalent to the Avogadro's number, 6.022 × 10^23.

That is, 1 mole of a compound = 6.022 × 10^23 molecules

Therefore,

1 mole of Na₂CO₃ = 6.022 × 10^23 molecules

Thus, we can calculate the number of molecules in 4.1 moles of Na₂CO₃

we get,

= 4.1 moles × 6.022 × 10^23 molecules

= 2.47 × 10^24 molecules

Hence, 4.1 moles of Na₂CO₃ contains 2.47 × 10^24 molecules

3 0

4 years ago

What does the nucleus do

mel-nik [20]

<span>The nucleus is the organelle present in eukaryotic cells with the main function in the control of all cell activities and maintaining the gene integrity. Namely, it contains the genetic material of the cell in the form of chromosomes (DNA molecules in complex with proteins). It is enclosed by the nuclear membrane which regulates the movement of proteins and RNA in and out of the nucleus.</span>

4 0

4 years ago