Question #8b799

2 Answers
Andrea B.
Apr 24, 2017

pH = 10,5

Explanation:

At first yuo must calculate the mole of anphetamine from its MM ( C9H13N=135; C= 12x9 = 108; H= 1x13 = 13; N=14) #mol = (mg/MM) = 230/ 135 = 1,7 10^(-3) mol# .#Kb = 10^-(pKb)= 10^(-4,2)= 6,3 10^(-5) #. # (OH^-) = sqrt (Cb x Kb) = sqrt (1,7 10^(-3) 6,3 10^(-5))= sqrt (1,07 10^(-7)) = 3,27 10^-4 # #pOH = -Log (OH^-) = -Log (3,27 10^-4 )= 3,48# pH = 14 -pOH = 14 -3,48 = 10,52

Andrea B.
Apr 24, 2017

At first yuo must calculate the mole of anphetamine from its MM ( C9H13N=135 g/mol; C= 12x9 = 108; H= 1x13 = 13; N=14) #mol = ((mg)/(MM)) = (230mg)/( 135g/(mol)) = 1,7 10^(-3) mol# .#Kb = 10^-(pKb)= 10^(-4,2)= 6,3 10^(-5) #. # (OH^-) = sqrt (Cb Kb) = sqrt (1,7 10^(-3) 6,3 10^(-5))= sqrt (1,07 10^(-7)) = 3,27 10^-4 # #pOH = -Log (OH^-) = -Log (3,27 10^-4 )= 3,48#
pH = 14 -pOH = 14 -3,48 = 10,52

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