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For the gas phase reaction, $\text{PCl}_5\text{(g)} \rightleftharpoons \text{PCl}_3\text{(g)} + \text{Cl}_2\text{(g)}$, which of the following conditions is correct?
The standard free energies of formation (in $\text{kJ/mol}$) at $298 \text{ K}$ are $-237.2$, $-394.4$, and $-8.2$ for $\text{H}_2\text{O(l)}$, $\text{CO}_2\text{(g)}$, and pentane (g), respectively. The value of $E^\circ_{\text{cell}}$ for the pentane-oxygen fuel cell is:
Which of the following are not state functions? (I) $q + W$ (II) $q$ (III) $W$ (IV) $H - TS$
What is the amount of work done by an ideal gas, if the gas expands isothermally from $10^{-3} \text{ m}^3$ to $10^{-2} \text{ m}^3$ at $300 \text{ K}$ against a constant pressure of $10^5 \text{ N m}^{-2}$?
Under isothermal condition, a gas at $300 \text{ K}$ expands from $0.1 \text{ L}$ to $0.25 \text{ L}$ against a constant external pressure of $2 \text{ bar}$. The work done by the gas is:
Assuming each reaction is carried out in an open container, the reaction that shows $\Delta H = \Delta E$ is:
From Kirchhoff's equation which factor affects the heat of reaction [MP PMT 1990]
The enthalpy of neutralization of which of the following acids and bases is nearly –13.6 Kcal [Roorkee 1999]
An engine operating between 150°C and 25°C takes 500 J heat from a higher temperature reservoir. If there are no frictional losses, then the work done by the engine is [MH CET 1999]:
An ideal gas expands in volume from $1 \times 10^{-3}$ m$^{3}$ to $1 \times 10^{-2}$ m$^{3}$ at 300 K against a constant pressure of $1 \times 10^{5}$ N m$^{-2}$. The work done is [AIEEE 2004]:
The absolute enthalpy of neutralisation of the reaction $MgO(s) + 2HCl(aq) ightarrow MgCl_{2}(aq) + H_{2}O(l)$ will be [CBSE PMT 2005]:
The work done to contract a gas in a cylinder is 462 joules. 128 joule energy is evolved in the process. What will be the internal energy change in the process? [MP PMT 2003]
Based on the following thermochemical equations: (i) $H_{2}O(g) + C(s) ightarrow CO(g) + H_{2}(g); \Delta H = 131 ext{ kJ}$ (ii) $CO(g) + rac{1}{2}O_{2}(g) ightarrow CO_{2}(g); \Delta H = -282 ext{ kJ}$ (iii) $H_{2}(g) + rac{1}{2}O_{2}(g) ightarrow H_{2}O(g); \Delta H = -242 ext{ kJ}$ The value of $X$ for the reaction $C(s) + O_{2}(g) ightarrow CO_{2}(g); \Delta H = X ext{ kJ}$ is [CBSE PMT 1992]:
Which of the following equations correctly represents the standard heat of formation (ΔfH°) of methane [IIT JEE (Screening) 1992]?
The freezing point depression constant ($K_f$) of benzene is 5.12 K kg $mol^{-1}$. The freezing point depression for the solution of molality 0.078 m containing a non-electrolyte solute in benzene is (rounded off upto two decimal places) :
A system is changed from state A to state B by one path and from B to A by another path. If $E_{1}$ and $E_{2}$ are the corresponding changes in internal energy, then [Pb. PMT 2001]:
If for a certain reaction $\Delta_r H$ is $30\text{ kJ mol}^{-1}$ at $450\text{ K}$, the value of $\Delta_r S$ (in $\text{J K}^{-1}\text{ mol}^{-1}$) for which the same reaction will be spontaneous at the same temperature is:
The work done during the expansion of a gas from a volume of $4\text{ dm}^3$ to $6\text{ dm}^3$ against a constant external pressure of $3\text{ atm}$ is:
Equal volumes of two monoatomic gases, A and B, at same temperature and pressure are mixed. The ratio of specific heats ($C_p/C_v$) of the mixture will be:
One mole of an ideal gas at $300\text{ K}$ is expanded isothermally from an initial volume of $1\text{ litre}$ to $10\text{ litres}$. The $\Delta E$ for this process is: ($R = 2\text{ cal mol}^{-1}\text{K}^{-1}$)