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QJEEM21Ch3280: JEE Main 2021 Chemistry - Class 11 JEEM21Ch3280 Solution: 0.01 moles of a weak acid HA (K a = 2.0 10 6 ) is dissolved in…

0.01 moles of a weak acid HA (Ka = 2.0 ×\times 10 −- 6) is dissolved in 1.0 L of 0.1 M HCl solution. The degree of dissociation of HA is __________ ×\times 10 −- 5 (Round off to the Nearest Integer).

[Neglect volume change on adding HA. Assume degree of dissociation <<1 ]

Step-by-Step Verified Solution

JEE Main 2021 (Online) 17th March Morning Shift Chemistry - Chemical Equilibrium Question 54 English Explanation

Now,

Ka=[H+][A−][HA]{K_a} = {{[{H^ + }][{A^ - }]} \over {[HA]}}

⇒2×10−6=(0.1)(10−2α)10−2\Rightarrow 2 \times {10^{ - 6}} = {{(0.1)({{10}^{ - 2}}\alpha )} \over {{{10}^{ - 2}}}}

⇒α=2×10−5\Rightarrow \alpha = 2 \times {10^{ - 5}}

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