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JEE Main 2021 (Online) 27th July Morning Shift
Numerical
+4
-1
The conductivity of a weak acid HA of concentration 0.001 mol L$$-$$1 is 2.0 $$\times$$ 10$$-$$5 S cm$$-$$1. If $$\Lambda _m^o$$(HA) = 190 S cm2 mol$$-$$1, the ionization constant (Ka) of HA is equal to ______________ $$\times$$ 10$$-$$6. (Round off to the Nearest Integer)
2
JEE Main 2021 (Online) 25th July Morning Shift
Numerical
+4
-1
Consider the cell at 25$$^\circ$$C

Zn | Zn2+ (aq), (1M) || Fe3+ (aq), Fe2+ (aq) | Pt(s)

The fraction of total iron present as Fe3+ ion at the cell potential of 1.500 V is x $$\times$$ 10$$-$$2. The value of x is ______________. (Nearest integer)

(Given : $$E_{F{e^{3 + }}/F{e^{2 + }}}^0 = 0.77V$$, $$E_{Z{n^{2 + }}/Zn}^0 = - 0.76V$$)
3
JEE Main 2021 (Online) 22th July Evening Shift
Numerical
+4
-1
Assume a cell with the following reaction

$$C{u_{(s)}} + 2A{g^ + }(1 \times {10^{ - 3}}M) \to C{u^{2 + }}(0.250M) + 2A{g_{(s)}}$$

$$E_{cell}^\Theta = 2.97$$ V

Ecell for the above reaction is ______________ V. (Nearest integer)

[Given : log 2.5 = 0.3979, T = 298 K]
4
JEE Main 2021 (Online) 20th July Evening Shift
Numerical
+4
-1
Potassium chlorate is prepared by electrolysis of KCl in basic solution as shown by following equation.

6OH$$-$$ + Cl$$-$$ $$\to$$ ClO3$$-$$ + 3H2O + 6e$$-$$

A current of xA has to be passed for 10h to produce 10.0g of potassium chlorate. The value of x is ____________. (Nearest integer)

(Molar mass of KClO3 = 122.6 g mol$$-$$1, F = 96500 C)