A volume of x mL of 5 M NaHCO₃ solution was mixed with 10 mL of 2 M H₂CO₃ solution to make an electrolytic buffer. If the same buffer was used in the following electrochemical cell to record a cell potential of 235.3 mV, then the value of x = ______ mL (nearest integer).

Sn(s) | Sn(OH)₆²⁻ (0.5 M) | HSnO₂⁻ (0.05 M) | OH⁻ | Bi₂O₃(s) | Bi(s)

Consider up to one place of decimal for intermediate calculations

For strong electrolyte $\Lambda_m$ increases slowly with dilution and can be represented by the equation

$$\Lambda_m = \Lambda_m^\circ - A c^{1/2}$$

Molar conductivity values of the solutions of strong electrolyte AB at 18°C are given below :

The value of constant A based on the above data [in S cm² mol^-1/(mol/L)^1/2] unit is ________.

Two positively charged particles $m_1$ and $m_2$ have been accelerated across the same potential difference of 200 keV as shown below.

[Given mass of $m_1 = 1$ amu and $m_2 = 4$ amu]

The deBroglie wavelength of $m_1$ will be $x$ times of $m_2$. The value of $x$ is __________ (nearest integer)

A → B (first reaction)

C → D (second reaction)

Consider the above two first-order reactions. The rate constant for first reaction at 500 K is double of the same at 300 K. At 500 K, 50% of the reaction becomes complete in 2 hour. The activation energy of the second reaction is half of that of first reaction. If the rate constant at 500 K of the second reaction becomes double of the rate constant of first reaction at the same temperature; then rate constant for the second reaction at 300 K is _______ × 10^-1 hour^-1 (nearest integer).