Leaching of $Ag_2S$ is carried out by heating it with a dilute solution of

Sodium and copper have work functions $2.3 \ eV$ and $4.5 \ eV$ respectively. The ratio of the threshold wavelength of sodium to that of copper is nearest to:

Assume each reaction is carried out in an open container. For which reaction will $\Delta H = \Delta E$?

$CH_3-CH_2-CH=O$ $\xrightarrow[(2) H^{+}]{(1) \text{Tollen's reagent}} X$ $\xrightarrow[(2) \text{dry distillation}]{(1) Ca(OH)_2} Y$
$Y$ is:

Which of the following is an acidic salt?

Product $(A)$ is