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Grade 12th PassPhysical Chemistry

Plz ans. the question which is in attachment. Plzzzzzzzzzzzzz.

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Profile image of Parth Verma
8 Years agoGrade 12th Pass
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1 Answer

Profile image of Arun
8 Years ago
Dear Parth
 
After the reaction: 0.02 mol CH3NH2 and 0.08 mol CH3NH3
by Henderson-Hasselbalch Equation: 
pH = pKa + log (base/acid) 
pKb = - log 5 x 10?4 
= 3.30103 
pKa = 14 - 3.30103 
= 10.69897 
pH = 10.69897 + log (0.02 / 0.08)
pH = 10.69897 + (-0.60206) 
pH = 10.09691 
Antilog the pH to get the H+ conc. which will be = 8 x 10?¹¹ M
 
Regards
Arun (askIITians forum expert)