1. Tardigrade
  2. Question
  3. Chemistry
  4. 20 mL of 0.1 MH2SO4 solution is added to 30 mL of 0.2 M NH4OH solution. The pH of the resulatant mixture is: [pkb of NH4OH = 4.7].

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. $20\, mL$ of $0.1 \; MH_2SO_4$ solution is added to $30\, mL$ of $0.2 \; M \; NH4OH $ solution. The $pH$ of the resulatant mixture is : $[pkb \; of \; NH_4OH = 4.7]$.

JEE MainJEE Main 2019Equilibrium

Solution:

$20\, ml\, 0 .1\, M\, H _2 SO _4 \Rightarrow \eta_{ H ^{+}}=4$
$30\, ml\, 0 .2\, M\, NH _4 OH \Rightarrow \eta_{ NH _4 OH }=6$
image
$pOH =pK_{b} +\log \frac{NH^{+}_{4}}{NH_{4}OH} $
$= 4.7 + \log \; 2$
$= 4.7 + 0.3 = 5$
$pH = 14 - 5 = 9$