1
JEE Main 2021 (Online) 26th August Evening Shift
Numerical
+4
-1
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)
2
JEE Main 2021 (Online) 26th August Evening Shift
Numerical
+4
-1
The reaction rate for the reaction

[PtCl4]2$$-$$ + H2O $$\rightleftharpoons$$ [Pt(H2O)Cl3]$$-$$ + Cl$$-$$

was measured as a function of concentrations of different species. It was observed that $${{ - d\left[ {{{\left[ {PtC{l_4}} \right]}^{2 - }}} \right]} \over {dt}} = 4.8 \times {10^{ - 5}}\left[ {{{\left[ {PtC{l_4}} \right]}^{2 - }}} \right] - 2.4 \times {10^{ - 3}}\left[ {{{\left[ {Pt({H_2}O)C{l_3}} \right]}^ - }} \right]\left[ {C{l^ - }} \right]$$.

where square brackets are used to denote molar concentrations. The equilibrium constant Kc = ____________ . (Nearest integer)
3
JEE Main 2021 (Online) 26th August Morning Shift
Numerical
+4
-1
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]
4
JEE Main 2021 (Online) 27th July Evening Shift
Numerical
+4
-1
The equilibrium constant for the reaction

A(s) $$\rightleftharpoons$$ M(s) + $${1 \over 2}$$O2(g)

is Kp = 4. At equilibrium, the partial pressure of O2 is _________ atm. (Round off to the nearest integer)