Problem: Amphetamine(C9H13N) is a weak base with a pK b of 4.2?Calculate the pH of a solution containing an amphetamine concentration of 205 mg/L.

FREE Expert Solution

Step 1

[B] = 205 mg ×10-3 g1 mg×1 mol135.2062 g1 L = 1.5162x10-3 M


Step 2


Step 3


Kb = 10-pKbKb =104.2

Kb = 15848


Step 4


Kb =[HB][OH-][B]6.3096×10-5 = (x)(x)1.5163×10-3 -x(6.3096×10-5)(1.5163×10-3 -x) = x2x2 + 6.3096×10-5 x - (6.3096×10-5)(1.5163×10-3) = 0

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Problem Details

Amphetamine(C9H13N) is a weak base with a pK b of 4.2?

Calculate the pH of a solution containing an amphetamine concentration of 205 mg/L.

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What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Weak Bases concept. If you need more Weak Bases practice, you can also practice Weak Bases practice problems.

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Based on our data, we think this problem is relevant for Professor Staff's class at UIC.