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2 years ago

Methylamine (ch3nh2) is a weakly basic compound. calculate the kb for methylamine if a 0.253 m solution is 4.07% ionized.

1 answer:

8 0

Answer is: Kb for methylamine is 4.37·10⁻⁴.<span>
Chemical reaction: CH</span>₃NH₂ + H₂O → CH₃NH₃⁺ + OH⁻.
c(CH₃NH₂) = 0.253 M.
α = 4.07% ÷ 100% = 0.0407.
[CH₃NH₃⁺] = [OH⁻] = c(CH₃NH₂) · α.
[CH₃NH₃⁺] = [OH⁻] = 0.253 M · 0.0407.
[CH₃NH₃⁺] = [OH⁻] = 0.0103 M.
[CH₃NH₂] = 0.253 M - 0.0103 M.
[CH₃NH₂] = 0.2427 M.
Kb = [CH₃NH₃⁺] · [OH⁻] / [CH₃NH₂].
Kb = (0.0103 M)² / 0.2427 M.
Kb = 4.37·10⁻⁴.

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2 years ago

Explain why c6h5ch2ch2br is not formed during the radical bromination of c6h5ch2ch3. select the single best answer.

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2 years ago

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2 years ago

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A sample of bismuth weighing 0.687 g was converted to bismuth chloride by reacting it first with HNO3, and then with HCI, follow

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Answer:

The empirical formula is BiCl3

% Bi = 66.27 %

Explanation:

Step 1: Data given

Mass of bismuth = 0.687 grams

Mass of bismuth chloride produced = 1.032 grams

Molar mass of bismuth = 208.98 g/mol

Molar mass of bismuth chloride = 315.33 g/mol

Step 2: The balanced equation

Step 3: Calculate moles of Bi

Moles Bi = mass Bi / molar mass Bi

Moles Bi = 0.687 grams / 208.98 g/mol

Moles Bi = 0.00329 moles

Step 4: Calculate moles of Cl

Mass of Cl = 1.032 - 0.687 = 0.345 moles

Moles Cl = 0.345 moles / 35.45 g/mol

Moles Cl = 0.00973 moles Cl

Step 5: Calculate mol ratio

We divide by the smaller number of moles:

Bi: 0.00329 / 0.00329 = 1

Cl: 0.0097The empirical formula is BiCl33/0.00329 = 3

Step 6: Calculate molar mass of BiCl3

Molar mass = 208.98 + 3*35.45 = 315.33 g/mol

Step 7: Calculate percent of Bi

% Bi = (208.98 / 315.33) * 100%

% Bi = 66.27 %

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