Physical Chemistry Questions

A reaction occurs spontaneously if :

Which of the following pairs of a chemical reaction is certain to result in a spontaneous reaction ?

The vapour pressure of two liquids P and Q are 80 and 60 torr, respectively. The total vapour pressure of solution obtained by mixing 3 moles of P and 2 moles of Q would be :

In which of the following reactions, standard reaction entropy change ($\Delta S^{\circ }$) is positive and standard Gibb’s energy change ($\Delta G^{\circ }$) decreases sharply with increasing temperature?

Which is the correct order of increasing energy of the listed orbitals in the atom of titanium? (At. No. $Z=22$)

Standard enthalpy of vapourisation ${\Delta }_{\text{vap}}{H}^{\circ }$ for water at $100^{\circ }\text{C}$ is $40.66\text{kJ/mol}$. The internal energy of vapourisation of water at $100^{\circ }\text{C}$ (in $\text{kJ/mol}$) is:

The formation of the oxide ion, ${\text{O}}^{2-}(g)$, from oxygen atom requires first an exothermic and then an endothermic step as shown below:$\text{O}(g)+e^{-}⟶{\text{O}}^{-}(g);{\Delta }_f{H}^{\ominus }=-141{\text{kJ mol}}^{-1}$${\text{O}}^{-}(g)+e^{-}⟶{\text{O}}^{2-}(g);{\Delta }_f{H}^{\ominus }=+780{\text{kJ mol}}^{-1}$ Thus the process of formation of ${\text{O}}^{2-}$ in gas phase is unfavourable though ${\text{O}}^{2-}$ is isoelectronic with neon. It is due to the fact that:

If the equilibrium constant for ${\text{N}}_2(g)+{\text{O}}_2(g)\rightleftharpoons 2\text{NO}(g)$ is $K$, the equilibrium constant for $\frac{1}{2}{\text{N}}_2(g)+\frac{1}{2}{\text{O}}_2(g)\rightleftharpoons \text{NO}(g)$ will be:

Which one of the following pairs of solution is not an acidic buffer?

Aqueous solution of which of the following compounds is the best conductor of electric current?

The number of water molecules is maximum in:

The vacant space in bcc lattice unit cell is:

If Avogadro number $N_A$, is changed from $6.022\times 10^{23}{\text{mol}}^{-1}$ to $6.022\times 10^{20}{\text{mol}}^{-1}$, this would change:

A gas such as carbon monoxide would be most likely to obey the ideal gas law at:

The heat of combustion of carbon to ${\text{CO}}_2$ is $-393.5\text{kJ/mol}$. The heat released upon formation of $35.2\text{g}$ of ${\text{CO}}_2$ from carbon and oxygen gas is:

$20.0\text{g}$ of a magnesium carbonate sample decomposes on heating to give carbon dioxide and $8.0\text{g}$ magnesium oxide. What will be the percentage purity of magnesium carbonate in the sample? (Atomic weight: $\text{Mg}=24$, $\text{C}=12$, $\text{O}=16$)

What is the mole fraction of the solute in a $1.00m$ aqueous solution?

The correct statement regarding defects in crystalline solids is:

The rate constant of the reaction $\text{A}⟶\text{B}$ is $0.6\times 10^{-3}\text{mole per second}$. If the concentration of $\text{A}$ is $5\text{M}$, then concentration of $\text{B}$ after $20$ minutes is:

What is the pH of the resulting solution when equal volumes of $0.1\text{M NaOH}$ and $0.01\text{M HCl}$ are mixed?

What is the mass of the precipitate formed when $50\text{mL}$ of $16.9\%$ solution of ${\text{AgNO}}_3$ is mixed with $50\text{mL}$ of $5.8\%$ $\text{NaCl}$ solution?

At 25°C, the dissociation constant of a base, BOH, is 1.0 x 10^-12. The concentration of hydroxyl ions in 0.01 M aqueous solution of the base would be :

pH of a saturated solution of ${\text{Ba(OH)}}_2$ is 12. The value of solubility product ($K_{sp}$) of ${\text{Ba(OH)}}_2$ is:

For a first order reaction A → B, the reaction rate at reactant concentration of 0.01 M is found to be 2.0 x 10^-5 mol L^-1 s^-1. The half life period of the reaction is :

$p_A$ and $p_B$ are the vapour pressure of pure liquid components $A$ and $B$, respectively, of an ideal binary solution. If $x_A$ represents the mole fraction of component $A$, the total pressure of the solution will be:

A metal crystallizes with a face-centered cubic (FCC) lattice. The edge of the unit cell is $408\text{pm}$. The diameter of the metal atom is:

Equimolar solutions of the following substances were prepared separately. Which one of these will record the highest pH value?

The enthalpy of fusion of water is $1.435\text{kcal/mol}$. The molar entropy change for the melting of ice at $0^{\circ }\text{C}$ is:

Limiting molar conductivity of ${\text{NH}}_4\text{OH}$ (i.e., ${\Lambda }_m^{\circ }({\text{NH}}_4\text{OH})$) is equal to:

In Freundlich Adsorption isotherm, the value of $1/n$ is:

Buffer solutions have constant acidity and alkalinity because:

In a zero-order reaction for every $10^{\circ }$ rise of temperature, the rate is doubled. If the temperature is increased from $10^{\circ }\text{C}$ to $100^{\circ }\text{C}$, the rate of the reaction will become:

$50\text{mL}$ of each gas $A$ and of gas $B$ takes $150$ and $200$ seconds respectively for effusing through a pin hole under the similar conditions. If molecular mass of gas $B$ is $36$, the molecular mass of gas $A$ will be:

The protecting power of lyophilic colloidal sol is expressed in terms of:

The ease of adsorption of the hydrated alkali metal ions on an ion-exchange resin follows the order:

Which one of the following statements is INCORRECT about enzyme catalysis?

Maximum number of electrons in a subshell with $l=3$ and $n=4$ is:

The correct set of four quantum numbers for the valence electron of rubidium atom ($Z=37$) is:

In a reaction, $A+B\to \text{Product}$, rate is doubled when the concentration of $B$ is doubled, and rate increases by a factor of $8$ when the concentrations of both the reactants ($A$ and $B$) are doubled. The rate law for the reaction can be written as:

The number of octahedral void(s) per atom present in a cubic close-packed structure is: