What is the mobile phase in chromatography

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

1 year ago

1 Na2CO3(aq) + 1 CaCl2(aq) → 1 CaCO3(s) + 2 NaCl(aq) 4. Use the balanced chemical equation from the last question to solve this

LenKa [72]

<h3>Answer:</h3>

0.6 g NaCl

<h3>General Formulas and Concepts:</h3>

<u>Math</u>

<u>Pre-Algebra</u>

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right

<u>Chemistry</u>

<u>Atomic Structure</u>

Reading a Periodic Table

<u>Stoichiometry</u>

Using Dimensional Analysis

<h3>Explanation:</h3>

<u>Step 1: Define</u>

[RxN - Balanced] Na₂CO₃ (aq) + CaCl₂ (aq) → CaCO₃ (s) + 2NaCl (aq)

[Given] 0.5 g Na₂CO₃ reacted with excess CaCl₂

<u>Step 2: Identify Conversions</u>

[RxN] Na₂CO₃ → 2NaCl

Molar Mass of Na - 22.99 g/mol

Molar Mass of C - 12.01 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of Cl - 35.45 g/mol

Molar Mass of Na₂CO₃ - 2(22.99) + 12.01 + 3(16.00) = 105.99 g/mol

Molar Mass of NaCl - 22.99 + 35.45 = 58.44 g/mol

<u>Step 3: Stoichiometry</u>

Set up: $\displaystyle 0.5 \ g \ Na_2CO_3(\frac{1 \ mol \ Na_2CO_3}{105.99 \ g \ Na_2CO_3})(\frac{2 \ mol \ NaCl}{1 \ mol \ Na_2CO_3})(\frac{58.44 \ g \ NaCl}{1 \ mol \ NaCl})$
Multiply/Divide: $\displaystyle 0.551373 \ g \ NaCl$

<u>Step 4: Check</u>

<em>Follow sig fig rules and round. We are given 1 sig fig.</em>

0.551373 g NaCl ≈ 0.6 g NaCl

5 0

2 years ago

The thyroid, parathyroid, and thymus are located in the

Studentka2010 [4]

Answer:

The pineal, hypothalamus, and pituitary are located in the BRAIN

The thyroid, parathyroid, and thymus are located in the THROAT

The adrenals, pancreas, testes, and ovaries are located in the NEAR THE KIDNEY

Explanation:

The pineal, hypothalamus, and pituitary are located in the BRAIN

The thyroid, parathyroid, and thymus are located in the THROAT

The adrenals, pancreas, testes, and ovaries are located in the NEAR THE KIDNEY

3 0

3 years ago

Oxalic acid is a polyprotic acid. Write balanced chemical equations for the sequence of reactions that oxalic acid can undergo w

tiny-mole [99]

The chemical formula of oxalic is $H_{2}C_{2}O_{4}$

When oxalic acid reacts with water, first, oxalic acid removes one proton and results in the formation of mono acids.

After that, in second step, oxalic acid in aqueous solution removes another proton which shows it is a polyprotic acid.

The chemical equations are: (the reactions occurs in two steps due to presence to hydrogen atoms).

When one proton is removed:

$H_{2}C_{2}O_{4} (aq)+H_{2}O (l)\rightarrow HC_{2}O_{4}^{-}(aq)+H_{3}O^{+}(aq)$

When another proton is removed:

$HC_{2}O_{4}^{-} (aq)+H_{2}O (l)\rightarrow C_{2}O_{4}^{2-}(aq)+H_{3}O^{+}(aq)$

The dissociation of oxalic acid in water in shown in the image.

8 0

3 years ago

How much is the mass of a man if

lesantik [10]

Answer:

50kg

Explanation:

Using the formula for potential energy, which is the amount of energy due to position;

P.E = m × g × h

Where;

m = mass (kg)

g = acceleration due to gravity (10m/s²)

h = height (metres)

According to the information provided in this question, m = ?, P.E = 2500J, h = 5m

Using P.E = m × g × h

m = P.E/gh

m = 2500/(5 × 10)

m = 2500/50

m = 50kg

The mass of the man is 50kg.

5 0

3 years ago