List of top Chemistry Questions on Gibbs Free Energy

The equilibrium constant $K_P$ of a homogenous equilibrium reaction is $1 \times 10^{-6}$ at $227^\circ C$. What is the value of $\Delta G^0$ of the reaction at the same temperature? ($R = 8.3\text{JK}^{-1}\text{mol}^{-1}$)}

The $\Delta H$ and $\Delta S$ values of a reaction are $400\,\mathrm{kJ\,mol^{-1}}$ and $200\,\mathrm{J\,K^{-1}\,mol^{-1}}$ respectively which are constant over a wide range of temperature. The temperature above which the reaction will be spontaneous is

At the transition temperature $T$, $A \rightleftharpoons B$ and $\Delta G^\circ = 105 - 35\log T$, where $A$ and $B$ are two states of substance $X$. The transition temperature in $^{\circ}C$ when pressure is 1 atm is ______.

Consider the following reactions sequence:

When the product (P) is subjected to Carius analysis using $ \text{AgNO}_3 $, 1.0 g of the product (P) will produce _______ g of the precipitate of $ \text{AgBr} $. (Nearest integer)}

For a certain reaction, $\Delta H = -210$ kJ and $\Delta S = -150$ J K$^{-1}$. Find the temperature so that $\Delta G = 0$.

Calculate $\Delta S_{\text{total}$ for a certain reaction if $\Delta H=-150\text{ kJ}$ and $\Delta S=32\text{ J K}^{-1}$ at 300 K.

Let us consider an endothermic reaction which is non-spontaneous at the freezing point of water. However, the reaction is spontaneous at the boiling point of water. Choose the correct option.

The standard cell potential of the following cell Zn|Zn²⁺ (aq)|Fe²⁺(aq)|Fe is 0.32 V. Calculate the standard Gibbs energy change for the reaction:Zn(s) + Fe²⁺(aq) → Zn²⁺(aq) + Fe(s)(Given: 1 F = 96487 C)

The standard electrode potential for Daniell cell is 1.1 V. The standard Gibbs free energy for the reaction Zn(s) + Cu$^{2+}$(aq) → Zn$^{2+}$(aq) + Cu(s) is approximately:

The number of incorrect statements from the following is _____
A. The electrical work that a reaction can perform at constant pressure and temperature is equal to the reaction Gibbs energy.
B. E°_cell is dependent on the pressure.
C. dE^θ cell/dT = Δ_rS^θ/nF
D. A cell is operating reversibly if the cell potential is exactly balanced by an opposing source of potential difference.

The number of incorrect statement/s about the black body from the following is _______
(A) Emit or absorb energy in the form of electromagnetic radiation
(B) Frequency distribution of the emitted radiation depends on temperature
(C) At a given temperature, intensity vs frequency curve passes through a maximum value
(D) The maximum of the intensity vs frequency curve is at a higher frequency at higher temperature compared to that at lower temperature

Gibbs energy vs T plot for the formation of oxides is given below.

For the given diagram, the correct statement is -

Consider the graph of Gibbs free energy G vs Extent of reaction. The number of statement/s from the following which are true with respect to points (a), (b) and (c) is…

A. Reaction is spontaneous at (a) and (b)
B. Reaction is at equilibrium at point (b) and nonspontaneous at point (c)
C. Reaction is spontaneous at (a) and nonspontaneous at (c)
D. Reaction is non-spontaneous at (a) and (b)

Which of the following expression is correct

Choose the correct answer :

1. The minimum energy that must be possessed by photons in order to produce the photoelectric effect with platinum metal is

[Given The threshold frequency of platinum is 1.3 × 10¹⁵ s^–1 and h = 6.6 × 10^–34 Js.]

$Cu(S)+Sn^{2+} (0.001M) Cu^{2+} (0.01M) + Sn(s)$
The Gibbs free energy change for the above reaction at 298 K is x × 10^-1 × kJ mol^-1. The value of x is ________ .[nearest integer]
[Given $E^{-}_{cu^{2+} / cu} = 0.34V; E^{-}_{Sn^{2+} / Sn} = - 0.14V; F = 96500 C ∼ mol^{-1}$]

A reaction is spontaneous at low temperature, but non-spontaneous at high temperature. Which of the following conditions is true for the chemical reaction?

The following reaction is performed at $298\, K ?$ $2 NO ( g )+ O _{2}( g ) \rightleftharpoons 2 NO _{2}( g )$ The standard free energy of formation of $NO ( g )$ is $86.6 \,kJ /\, mol$ at $298 \,K .$ What is the standard free energy of formation of $NO _{2}( g )$ at $298 \,K ?\left( K _{n}=1.6 \times 10^{12}\right)$

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