1
JEE Advanced 2020 Paper 2 Offline
Numerical
+4
-0
A solution of 0.1 M weak base (B) is titrated with 0.1 M of a strong acid (HA). The variation of pH of the solution with the volume of HA added is shown in the figure below. What is the pKb of the base? The neutralisation reaction is given by

$$B + HA\buildrel {} \over \longrightarrow B{H^ + } + {A^ - }$$

2
JEE Advanced 2020 Paper 2 Offline
Numerical
+4
-0
An acidified solution of 0.05 M Zn2+ is saturated with 0.1 M H2S. What is the minimum molar concentration (M) of H+ required to prevent the precipitation of ZnS?

Use Ksp(ZnS) = 1.25 $$\times$$ 10$$-$$22 and overall dissociation constant of

H2S, Knet = K1K2 = 1 $$\times$$ 10-21.
3
JEE Advanced 2020 Paper 1 Offline
Numerical
+4
-0
Consider the reaction,

A $$\rightleftharpoons$$ B

at 1000 K. At time t', the temperature of the system was increased to 2000 K and the system was allowed to reach equilibrium. Throughout this experiment the partial pressure of A was maintained at 1 bar. Given, below is the plot of the partial pressure of B with time. What is the ratio of the standard Gibbs energy of the reaction at 1000 K to that at 2000 K?

4
JEE Advanced 2019 Paper 1 Offline
Numerical
+3
-0
For the following reaction, the equilibrium constant Kc at 298 K is 1.6 $$\times$$ 1017.

Fe2+(aq) + S2-(aq) ⇌ FeS(s)

When equal volumes of

0.06 M Fe2+(aq) and 0.2 M S2$$-$$(aq)

solutions are mixed, the equilibrium concentration of Fe2+(aq) is found by Y $$\times$$ 10$$-$$17 M. The value of Y is .................