Answer:
pH = 10.38
Explanation:
∴ molar mass C9H13N = 135.21 g/mol
∴ pKb = - log Kb = 4.2
⇒ Kb = 6.309 E-5 = [OH-][C9H20O3N+] / [C9H13N]
∴ <em>C</em> sln = (205 mg/L )*(g/1000 mg)*(mol/135.21 g) = 1.516 E-3 M
mass balance:
⇒ <em>C</em> sln = 1.516 E-3 = [C9H20O3N+] + [C9H13N]......(1)
charge balance:
⇒ [C9H20O3N+] + [H3O+] = [OH-]; [H3O+] is neglected, come from water
⇒ [C9H20O3N+] = [OH-].......(2)
(2) in (1):
⇒ [C9H13N] = 1.516 E-3 - [OH-]
replacing in Kb:
⇒ Kb = 6.3096 E-5 = [OH-]² / (1.516 E-3 - [OH-])
⇒ [OH-]² + 6.3096 E-5[OH] - 7.26613 E-8 = 0
⇒ [OH-] = 2.3985 E-4 M
∴ pOH = - Log [OH-]
⇒ pOH = 3.62
⇒ pH = 14 - pOH = 14 - 3.62 = 10.38
First convert volume to mass:
mass = 0.789 g/mL * 155 mL = 122.295 g
Then convert mass to number of moles:
number of moles = 122.295 g * (1 mole / 46 g) = 2.66 moles
Using avogadros number, we get the molecules:
<span>number of molecules = 2.66 moles * 6.022 x 10^23 molecules
/ mole = 1.6 x 10^24 molecules</span>
Answer:
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Explanation:
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Answer:
Mass is 725.46g/cm
Explanation:
Mass = density × volume = 22.6g/cm^3 × 32.1cm^2 = 725.46g/cm
