To obtain silver from silver amalgam,it is heated in a vessel which is made of

How many moles of gaseous oxygen at one atmosphere are considered for the reaction with an element to plot a graph in an Ellingham diagram?

Gold is extracted by a hydrometallurgical process based on its property:

Write the chemical reactions involved in the extraction of gold by the cyanide process. Also,explain the role of zinc in this extraction.

Given are two statements,one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: Magnesium can reduce $Al_{2}O_{3}$ at a temperature below $1350^{\circ} C$,while above $1350^{\circ} C$ aluminium can reduce $MgO$.
Reason $R$: The melting and boiling points of magnesium are lower than those of aluminium.
In light of the above statements,choose the most appropriate answer from the options given below:

In the extraction of aluminium,the electrolyte used is: