$A$ balloon carries a total load of $185\; \text{kg}$ at normal pressure and temperature of $27^{\circ} \text{C}$. What load will the balloon carry on rising to a height at which the barometric pressure is $45\; \text{cm}$ of $\text{Hg}$ and the temperature is $-7^{\circ} \text{C}$? Assume the volume is constant. (in $\text{kg}$)

An insulated system contains $4$ moles of an ideal diatomic gas at temperature $T$. When a heat $Q$ is supplied to the gas,$2$ moles of the gas is dissociated into atoms and the temperature remains constant. Then the relation between $Q$ and $T$ is ($R=$ universal gas constant.)

As shown schematically in the figure,two vessels contain water solutions (at temperature $T$) of potassium permanganate $(KMnO_4)$ of different concentrations $n_1$ and $n_2$ $(n_1 > n_2)$ molecules per unit volume with $\Delta n = (n_1 - n_2) \ll n_1$. When they are connected by a tube of small length $\ell$ and cross-sectional area $S$,$KMnO_4$ starts to diffuse from the left to the right vessel through the tube. Consider the collection of molecules to behave as dilute ideal gases and the difference in their partial pressure in the two vessels causing the diffusion. The speed $v$ of the molecules is limited by the viscous force $-\beta v$ on each molecule,where $\beta$ is a constant. Neglecting all terms of the order $(\Delta n)^2$,which of the following is/are correct? ($k_B$ is the Boltzmann constant)
$(A)$ the force causing the molecules to move across the tube is $\Delta n k_B T S$
$(B)$ force balance implies $n_1 \beta v \ell = \Delta n k_B T$
$(C)$ total number of molecules going across the tube per sec is $\left(\frac{\Delta n}{\ell}\right)\left(\frac{k_B T}{\beta}\right) S$
$(D)$ rate of molecules getting transferred through the tube does not change with time

An ideal gas at pressure $P$ and temperature $T$ is expanding such that $PT^3 = \text{constant}$. The coefficient of volume expansion of the gas is . . . . . . .

The average translational kinetic energy of $N$ molecules in a gas is $E_1$. The kinetic energy of the electron $(e)$ accelerated from rest through potential difference $V$ volt is $E_2$. The temperature at which $E_1=E_2$ is possible is ( $R=$ gas constant,$N=$ number of molecules).

Two closed vessels of same volume are joined through a narrow tube and both vessels are filled with air of pressure $90 \text{ kPa}$ and temperature $400 \text{ K}$. Keeping the temperature of one vessel constant at $400 \text{ K}$, the temperature of the second vessel is raised to $500 \text{ K}$. The final pressure in the vessels is . . . . . . $\text{ kPa}$.