Question

$\Delta G=\Delta H-T\Delta S$ was given by :

• A. Faraday
• B. Kirchhoff
• C. Einstein
• D. Gibbs-Helmholtz

Answer 1

Answer: (D)

Gibbs Helmholtz equation
$\Delta G=\Delta H-T\Delta S$
$\Delta S=$ Gibb's free energy
$\Delta H=$ enthalpy change
$\Delta S=$ entropy change
This equation is very helpful in producting the spontaneity of a process.
$\to$ If $\Delta G$ is negative i.e., $\Delta G<0$, indicate that the process is spontaneous
$\to$ If $\Delta G=0$ i.e., $T\Delta S=0,\Delta S=0$, process is in equilibrium.
$\to \Delta G$ is positive i.e., $\Delta G>0$, process is non spontaneous.
Faraday gave the law of electrolysis
$I$ law : $w=$ Zit
$w=$ substance deposited
$i=$ current (ampere)
$t=$ time $(sec)$
$Z=$ electrochemical equivalent
$II$ law : $\frac{w_1}{w_2}=\frac{Z_1}{Z_2}=\frac{E_1}{E_2}$
$w_1,w_2$ are the masses of substances liberated by passing the same quantity of electricity and $E_1$ and $E_2$ are their equivalent masses.
Einstein gave the energy relationship
$E=m{c}^2\left(c=3\times 10^{8}m/s\right)$
$m=$ mass
$E=$ energy