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WINSTONCH [101]
3 years ago
15

What is the kb of a 0.0200 m ( at equilibrium) solution of methyl amine, ch3nh2, that has a ph of 11.40?

Chemistry
1 answer:
marin [14]3 years ago
8 0
Answer: Kb = 3.15 × 10 ⁻⁴

Explanation:


This is how you calculate Kb for this reaction.

1) Equilibrium equation:

CH₃NH₂ + H₂O ⇄ CH₃NH₃⁺ + OH⁻

2) Kb = [CH₃NH₃⁺]  [OH⁻] / [CH₃NH₂] ↔ all the spieces in equilibrium


3) From the stoichiometry [CH₃NH₃⁺] = [OH⁻]

Then, Kb = [OH⁻]  [OH⁻] / [CH₃NH₂] = [OH⁻]² / [CH₃NH₂]

4) You get [OH⁻] from the pH in this way:

pOH + pOH = 14 ⇒ pOH = 14 - pH = 14 - 11.40 = 2.60

pOH = - log [OH⁻] = 2.60 ⇒ [OH⁻] = 10^(-2.6) = 0.002512

5) [CH₃NH₂] in equilibrium is given: 0.0200M


6) Now compute:

Kb = (0.002512)² / 0.0200 = 3.15 × 10 ⁻⁴




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Explain why the electron configuration of 2-3-1 represents an atom in an excited state?
baherus [9]

Answer:

See explanation

Explanation:

If we look at the electron configuration closely, we will discover that the element must have had a ground state electron configuration of 2,4.

This is because, the innermost shell usually holds two electrons while the outer shells hold eight electrons each. The four electrons must be accommodated in the second shell in the ground state configuration of the compound.

However, when the atom is excited, one electron from this shell may move to the third shell to give the excited state configuration 2-3-1 as shown in the question.

6 0
3 years ago
Find the volume of a gas at standard pressure if its volume at 1.9 atm is 80 ml?
kogti [31]

Answer:

1.5 × 10² mL

Explanation:

Step 1: Given data

  • Initial pressure of the gas (P₁): 1.9 atm
  • Initial volume of the gas (V₁): 80 mL
  • Final pressure of the gas (P₂): 1.0 atm (standard pressure)
  • Final volume of the gas (V₂): ?

Step 2: Calculate the final volume of the gas

For an ideal gas, we can calculate the final volume of the gas using Boyle's law.

P₁ × V₁ = P₂ × V₂

V₂ = P₁ × V₁/P₂

V₂ = 1.9 atm × 80 mL/1.0 atm

V₂ = 1.5 × 10² mL

Since the pressure decreased, the volume of the gas increased.

6 0
3 years ago
What is the ratio of effusion rates for the lightest gas, h2, to the heaviest known gas, uf6?
andriy [413]

The ratio of effusion rates for the lightest gas H₂ to the heaviest known gas UF₆ is 13.21 to 1

<h3>What is effusion?</h3>

Effusion is a process by which a gas escapes from its container through a tiny hole into evacuated space.

Rate of effusion ∝ 1/√Ц, (where Ц is molar mass)

Rate H₂ = 1/√ЦH₂

Rate UF₆ = 1/√ЦUF₆

Therefore, Rate H₂/ Rate UF₆ = √ЦH₂/√ЦUF₆

ЦH₂= 2.016 g/mol

ЦUF₆= 352.04 g/mol

Rate H₂ / Rate UF₆ = √352.04/√2.016 = 18.76/1.42

Rate H₂ / Rate UF₆ = 13.21

Therefore, H₂ is lower mass than UF₆. Thus H₂ gas will effuse 13 times more faster than UF₆ because the most probable speed of H₂ molecule is higher; therefore, more molecules escapes per unit time.

learn more about effusion rate: brainly.com/question/28371955

#SPJ1

8 0
1 year ago
Given that nitrogen forms three bonds with hydrogen to make <img src="https://tex.z-dn.net/?f=NH_%7B3%7D" id="TexFormula1" title
lbvjy [14]

Answer:

Three hydrogen atoms to form PH₃.

Explanation:

Hello!

In this case, since the elements belonging to the nitrogen family (N, P, As, Sb and Bi) show five valence electrons, because there are five electrons at their outer shell, it is clear that if phosphorous bonds with hydrogen, it is going to require the same amount of oxygen atoms (3) because elements having five valence electrons need 3 bonds in order to attain the octet (5+3=8).

Therefore the compound would be:

PH_3

Which is phosphine.

Best regards!

3 0
3 years ago
Which two characteristics describe all animals
Maru [420]

All animals can be dangerous and they would fight for their family. (This might be wrong)

5 0
3 years ago
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