The diagram shows the energy levels for an electron in a certain atom. Which transition shown represents the emission of a photon with the most energy?

The reaction $2A_{(g)} + B_{(g)} \rightleftharpoons 3C_{(g)} + D_{(g)}$ is begun with the concentrations of $A$ and $B$ both at an initial value of $1.00 \ M$. When equilibrium is reached,the concentration of $D$ is measured and found to be $0.25 \ M$. The value for the equilibrium constant for this reaction is given by the expression

The pioneer country in the production of fuel-alcohol is

For the following cell reaction,$Ag|Ag^{+}|AgCl|Cl^{-}|Cl_2, Pt$
$\Delta G_f^{\circ}(AgCl) = -109 \ kJ / mol$
$\Delta G_f^{\circ}(Cl^{-}) = -129 \ kJ / mol$
$\Delta G_f^{\circ}(Ag^{+}) = 78 \ kJ / mol$
The $E^{\circ}$ of the cell is:

The equation of the pair of lines passing through the origin whose sum and product of slopes are respectively the arithmetic mean and geometric mean of $4$ and $9$ is

The product obtained at the anode when $50 \%$ $H_2SO_4$ aqueous solution is electrolysed using platinum electrodes is: