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1

JEE Main 2021 (Online) 27th August Morning Shift

Numerical
The number of moles of NH3, that must be added to 2L of 0.80 M AgNO3 in order to reduce the concentration of Ag+ ions to 5.0 $$\times$$ 10$$-$$8 M (Kformation for [Ag(NH3)2]+ = 1.0 $$\times$$ 108) is ____________. (Nearest integer)

[Assume no volume change on adding NH3]
Your Input ________

Answer

Correct Answer is 4

Explanation

Let moles added = a


$${{0.8} \over {(5 \times {{10}^{ - 8}})\left( {{a \over 2} - 1.6} \right)}} = {10^8}$$

$$\Rightarrow$$ $${{a \over 2}}$$ $$-$$ 1.6 = 0.4 $$\Rightarrow$$ a = 4
2

JEE Main 2021 (Online) 26th August Evening Shift

Numerical
The equilibrium constant Kc at 298 K for the reaction A + B $$\rightleftharpoons$$ C + D is 100. Starting with an equimolar solution with concentrations of A, B, C and D all equal to 1M, the equilibrium concentration of D is ___________ $$\times$$ 10$$-$$2 M. (Nearest integer)
Your Input ________

Answer

Correct Answer is 182

Explanation

$$\therefore$$ $${K_C} = {\left( {{{1 + x} \over {1 - x}}} \right)^2}$$

$$100 = {\left( {{{1 + x} \over {1 - x}}} \right)^2}$$

$${{1 + x} \over {1 - x}} = 10$$

$$x = {9 \over {11}}$$

Moles of D = 1 + x

$$ = 1 + {9 \over {11}} = {{20} \over {11}}$$

$$ = 1.818 = 181.8 \times {10^{ - 2}} = 181.8 \times {10^{ - 2}}$$

$$ \cong 182 \times {10^{ - 2}}$$ M

3

JEE Main 2021 (Online) 26th August Morning Shift

Numerical
The OH$$-$$ concentration in a mixture of 5.0 mL of 0.0504 M NH4Cl and 2 mL of 0.0210 M NH3 solution is x $$\times$$ 10$$-$$6 M. The value of x is ___________. (Nearest integer)

[Given Kw = 1 $$\times$$ 10$$-$$14 and Kb = 1.8 $$\times$$ 10$$-$$5]
Your Input ________

Answer

Correct Answer is 3

Explanation

$$\left[ {NH_4^ + } \right]$$ = 0.0504 & [NH3] = 0.0210

So, $${K_b} = {{[NH_4^ + ][H{O^ - }]} \over {[N{H_3}]}}$$

$$[H{O^ - }] = {{{K_b} \times [N{H_3}]} \over {[NH_4^ + ]}} = 1.8 \times {10^{ - 5}} \times {2 \over 5} \times {{210} \over {504}} = 3 \times {10^{ - 6}}$$
4

JEE Main 2021 (Online) 27th July Evening Shift

Numerical
2SO2(g) + O2(g) $$\to$$ 2SO3(g)

The above reaction is carried out in a vessel starting with partial pressure PSO2 = 250 m bar, PO2 = 750 m bar and PSO3 = 0 bar. When the reaction is complete, the total pressure in the reaction vessel is _______ m bar. (Round off of the nearest integer).
Your Input ________

Answer

Correct Answer is 875

Explanation

2SO2(g) + O2(g) $$\to$$ 2SO3(g)


$$\therefore$$ Final total pressure = 625 + 250 = 875 m bar

Questions Asked from Equilibrium

On those following papers in Numerical
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JEE Main 2021 (Online) 1st September Evening Shift (1)
JEE Main 2021 (Online) 31st August Evening Shift (2)
JEE Main 2021 (Online) 31st August Morning Shift (1)
JEE Main 2021 (Online) 27th August Evening Shift (1)
JEE Main 2021 (Online) 27th August Morning Shift (1)
JEE Main 2021 (Online) 26th August Evening Shift (1)
JEE Main 2021 (Online) 26th August Morning Shift (1)
JEE Main 2021 (Online) 27th July Evening Shift (2)
JEE Main 2021 (Online) 27th July Morning Shift (1)
JEE Main 2021 (Online) 25th July Evening Shift (1)
JEE Main 2021 (Online) 25th July Morning Shift (2)
JEE Main 2021 (Online) 22th July Evening Shift (1)
JEE Main 2021 (Online) 20th July Morning Shift (1)
JEE Main 2021 (Online) 18th March Evening Shift (2)
JEE Main 2021 (Online) 18th March Morning Shift (2)
JEE Main 2021 (Online) 17th March Evening Shift (1)
JEE Main 2021 (Online) 17th March Morning Shift (2)
JEE Main 2021 (Online) 16th March Evening Shift (1)
JEE Main 2021 (Online) 16th March Morning Shift (2)
JEE Main 2021 (Online) 26th February Evening Shift (2)
JEE Main 2021 (Online) 26th February Morning Shift (1)
JEE Main 2021 (Online) 24th February Evening Shift (2)
JEE Main 2021 (Online) 24th February Morning Shift (4)
JEE Main 2020 (Online) 5th September Evening Slot (1)
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JEE Main 2020 (Online) 9th January Evening Slot (1)
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