1
JEE Main 2020 (Online) 3rd September Morning Slot
+4
-1
An acidic buffer is obtained on mixing :
A
100 mL of 0.1 M HCl and 200 mL of 0.1 M CH3COONa
B
100 mL of 0.1 M HCl and 200 mL of 0.1 M NaCl
C
100 mL of 0.1 M CH3COOH and 100 mL of 0.1 M NaOH
D
100 mL of 0.1 M CH3COOH and 200 mL of 0.1 M NaOH
2
JEE Main 2020 (Online) 2nd September Morning Slot
+4
-1
For the following Assertion and Reason, the correct option is

Assertion (A): When Cu (II) and sulphide ions are mixed, they react together extremely quickly to give a solid.

Reason (R): The equilibrium constant of
Cu2+(aq) + S2–(aq) ⇌ CuS(s) is high because the solubility product is low.
A
(A) is false and (R) is true.
B
Both (A) and (R) are true but (R) is not the explanation for (A).
C
Both (A) and (R) are true and (R) is the explanation for (A).
D
Both (A) and (R) are false.
3
JEE Main 2020 (Online) 9th January Evening Slot
+4
-1
The solubility product of Cr(OH)3 at 298 K is 6.0 × 10–31. The concentration of hydroxide ions in a saturated solution of Cr(OH)3 will be :
A
(2.22 × 10–31)1/4
B
(4.86 × 10–29)1/4
C
(18 × 10–31)1/4
D
(18 × 10–31)1/2
4
JEE Main 2020 (Online) 9th January Morning Slot
+4
-1
The Ksp for the following dissociation is 1.6 × 10–5

$$PbC{l_{2(s)}} \leftrightharpoons Pb_{(aq)}^{2 + } + 2Cl_{(aq)}^ -$$

Which of the following choices is correct for a mixture of 300 mL 0.134 M Pb(NO3)2 and 100 mL 0.4 M NaCl ?
A
Q > Ksp
B
Not enough data provided
C
Q < Ksp
D
Q = Ksp
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