NEET UG 2003 — Physical Chemistry

For the reaction $\mathrm{C}_3 \mathrm{H}_8(g)+5 \mathrm{O}_2(g) \rightarrow 3 \mathrm{CO}_2(\mathrm{~g})+4 \mathrm{H}_2 \mathrm{O}(l)$ at constant temperature, $\Delta \mathrm{H}-\Delta \mathrm{E}$ is:

For which one of the following equations is $\Delta \mathrm{H}_{\text {react }}^{\circ}$ equal to $\Delta \mathrm{H}_f^{\circ}$ for the product?

Formation of a solution from two components can be considered as: (i) Pure solvent $\rightarrow$ separated solvent molecules $\Delta \mathrm{H}_1$ (ii) Pure solute $\rightarrow$ separated solute molecules, $\Delta \mathrm{H}_2$ (iii) Separated solvent and solute molecules $\rightarrow$ solution, $\Delta \mathrm{H}_3$ Solution so formed will be ideal of:

If the rate of the reaction is equal to the rate constant, the order of the reaction is:

In Haber process 3 litres of dihydrgen and 30 litres of dinitrogen were taken for reaction which yielded only $50 \%$ of the expected product. What will be the composition of gaseous mixture under the above said condition in the end?

On the basis of information available from the reaction $\frac{4}{3} \mathrm{Al}+\mathrm{O}_2 \rightarrow \frac{2}{3} \mathrm{Al}_2 \mathrm{O}_3, \Delta \mathrm{G}=-827 \mathrm{~kJ} \mathrm{mol}^{-1}$ of $\mathrm{O}_2$, the minimum e.m.f required to carry out an electrolysis of $\mathrm{Al}_2 \mathrm{O}_3$ is $(\mathrm{F}=$ $\left.96500 \mathrm{C} \mathrm{mol}^{-1}\right):$

Reaction $\mathrm{A} \rightarrow \mathrm{B}$ follows first order kinetics. The time taken for 0.8 mole of $A$ to produce 0.6 mole of $B$ is 1 hour. What is the time taken for conversion of 0.9 mole of A to produce 0.675 mole of $\mathrm{B}$ ?

The activation energy for a simple chemical reaction $\mathrm{A} \rightarrow \mathrm{B}$ is $\mathrm{E}_a$ in forward direction. The activation energy for reverse reaction:

The densities of graphite and diamond at $298 \mathrm{~K}$ are 2.25 and $3.31 \mathrm{gcm}^{-3}$, respectively. If the standard free energy difference $\left(\Delta \mathrm{G}^{\circ}\right)$ is equal to $1895 \mathrm{~J} \mathrm{~mol}^{-1}$, the pressure at which graphite will be transformed into diamond at $298 \mathrm{~K}$ is:

The e.m.f. of a Deniell cell at $298 \mathrm{~K}$ is $\mathrm{E}_1$ $$ \mathrm{Zn}\left|\begin{array}{c} \mathrm{ZnSO}_4 \\ (0.01 \mathrm{M}) \end{array}\right|\left|\begin{array}{c} \mathrm{CuSO}_4 \\ (0.01 \mathrm{M}) \end{array}\right| \mathrm{Cu} $$ When the concentration of $\mathrm{ZnSO}_4$ in 1.0 $\mathrm{M}$ and that of $\mathrm{CuSO}_4$ is $0.01 \mathrm{M}$, the e.m.f. changed to $\mathrm{E}_2$. What is the relationship between $E_1$ and $E_2$ ?

The following equilibrium are given: $$ \begin{array}{ll} \mathrm{N}_2+3 \mathrm{H}_2 \rightleftharpoons 2 \mathrm{NH}_3 & \mathrm{~K}_1 \\ \mathrm{~N}_2+\mathrm{O}_2 \rightleftharpoons 2 \mathrm{NO} & \mathrm{K}_2 \\ \mathrm{H}_2+\frac{1}{2} \mathrm{O}_2 \rightleftharpoons \mathrm{H}_2 \mathrm{O} & \mathrm{K}_3 \end{array} $$ The equilibrium constant of the reaction $$ 2 \mathrm{NH}_3+\frac{5}{2} \mathrm{O}_2 \rightleftharpoons 2 \mathrm{NO}+3 \mathrm{H}_2 \mathrm{O} $$ in terms of $\mathrm{K}_1, \mathrm{~K}_2$ and $\mathrm{K}_3$ is:

The ions $\mathrm{O}^{2-}, \mathrm{F}^{-}, \mathrm{Na}^{+}, \mathrm{Mg}^{2+}$ and $\mathrm{Al}^{3+}$ are isoelectronic. Their ionic radii show:

The molar heat capacity of water at constant, pressure, $\mathrm{C}$, is $75 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$. When 1.0 $\mathrm{kJ}$ of heat is supplied to $100 \mathrm{~g}$ of water which is free to expand, the increase in temperature of water is:

The radiosotope tritium $\left({ }_1^3 \mathrm{H}\right)$ has a lalf life of 12.3 years. If the initial amount of tritium is $32 \mathrm{mg}$, how many milligrams of it would remain after 49.2 years

The reaction quotient $(\mathrm{Q})$ for the reaction: $\mathrm{N}_{2(g)}+3 \mathrm{H}_{2(g)} \rightleftharpoons 2 \mathrm{NH}_{3(\mathrm{~g})}$ is given by $\mathrm{Q}=\frac{\left[\mathrm{NH}_3\right]^2}{\left[\mathrm{~N}_2\right]\left[\mathrm{H}_2\right]^3}$ The reaction will proceed from right to left if:

The solubility product of $\mathrm{Agl}$ at $25^{\circ} \mathrm{C}$ is $1.0 \times 10^{-16} \mathrm{~mol}^2 \mathrm{~L}^{-2}$. The solubility of $\mathrm{Agl}$ is $10^{-4} \mathrm{~N}$ solution of $\mathrm{KI}$ at $25^{\circ} \mathrm{C}$ is approximately (in $\mathrm{mol} \mathrm{L}^{\mathrm{1}}$ )

The temperature dependence of rate constant $(k)$ of a chemical reaction is written in terms of Arrhenius equation, $\mathrm{k}=\mathrm{A} \cdot e^{-\mathrm{Ea} / \mathrm{RT}}$. Activation energy $\left(\mathrm{E}_a\right)$ of the reaction can be calculated by ploting:

The value of Planck's constant is 6.63 $\times 10^{-34} \mathrm{Js}$. The velocity of light is $3.0 \times$ $10^8 \mathrm{~ms}^{-1}$. Which value is closest to the wavelength in nanometers of quantum of light with frequency of $8 \times 10^{15} \mathrm{~s}^{-1}$ ?

What is the entropy change (in $\mathrm{JK}^{-1} \mathrm{~mol}^{-1}$ ) when one mole of ice is converted into water at $0^{\circ} \mathrm{C}$ ? (The enthalpy change for the conversion of ice to liquid water is $6.0 \mathrm{~kJ} \mathrm{~mol}^{-1}$ at $0^{\circ} \mathrm{C}$ )

Which one of the following compounds is not a protonic acid?

Which one of the following statement is not true?