1
JEE Main 2023 (Online) 24th January Evening Shift
Numerical
+4
-1 If the pKa of lactic acid is 5, then the pH of 0.005 M calcium lactate solution at 25$$^\circ$$C is ___________ $$\times$$ 10$$^{-1}$$ (Nearest integer) 2
JEE Main 2023 (Online) 24th January Morning Shift
Numerical
+4
-1 The dissociation constant of acetic acid is $$x\times10^{-5}$$. When 25 mL of 0.2 $$\mathrm{M~CH_3COONa}$$ solution is mixed with 25 mL of 0.02 $$\mathrm{M~CH_3COOH}$$ solution, the pH of the resultant solution is found to be equal to 5. The value of $$x$$ is ____________

3
JEE Main 2022 (Online) 29th July Morning Shift
Numerical
+4
-1 If the solubility product of PbS is 8 $$\times$$ 10$$-$$28, then the solubility of PbS in pure water at 298 K is x $$\times$$ 10$$-$$16 mol L$$-$$1. The value of x is __________. (Nearest Integer)

[Given : $$\sqrt2$$ = 1.41]

4
JEE Main 2022 (Online) 28th July Evening Shift
Numerical
+4
-1 At $$600 \mathrm{~K}, 2 \mathrm{~mol}$$ of $$\mathrm{NO}$$ are mixed with $$1 \mathrm{~mol}$$ of $$\mathrm{O}_{2}$$.

$$2 \mathrm{NO}_{(\mathrm{g})}+\mathrm{O}_{2}(\mathrm{g}) \rightleftarrows 2 \mathrm{NO}_{2}(\mathrm{g})$$

The reaction occurring as above comes to equilibrium under a total pressure of 1 atm. Analysis of the system shows that $$0.6 \mathrm{~mol}$$ of oxygen are present at equilibrium. The equilibrium constant for the reaction is ________. (Nearest integer)

JEE Main Subjects
Physics
Mechanics
Electricity
Optics
Modern Physics
Chemistry
Physical Chemistry
Inorganic Chemistry
Organic Chemistry
Mathematics
Algebra
Trigonometry
Coordinate Geometry
Calculus
EXAM MAP
Joint Entrance Examination