Question

The mineral carnallite contains (i)_and(ii)_metals.(iii)__ is purified by cupellation and (iv)_ is purified by distillation.
(A) (i)- Calcium. (ii)- zinc, (iii)- mercury, (iv)- tin
(B) (i)- Calcium. (ii)- magnesium, (iii)- zinc, (iv)- lead
(C) (i)- Potassium. (ii)- calcium, (iii)- copper, (iv)- mercury
(D) (i)- Magnesium. (ii)- potassium, (iii)- silver, (iv)- mercury

Answer 1

As we know that metals generally occur in the form their oxides, sulphides, carbonates, sulphates, halides, etc. and the minerals are generally made of one or a mixture of elements. They are purified by a number of techniques like distillation and cupellation which is a techniques where ores and alloyed metals are processed under high temperature

Complete Step by step answer: As we know that the minerals are the solid substances which are naturally present and made up of one or more than one or a mixture of elements combined together except gold, silver and carbon because they make minerals on their own. Carnallite is one such mineral which is basically a hydrated mineral made up of Potassium Magnesium Chloride with a molecular formula $KMgC{l_3}.6({H_2}O)$.
Thus we can write the given statement as: The mineral carnallite contains (i) Magnesium and (ii) Potassium metals.
Now comes the cupellation process. We know that metals need to be purified from their impure forms or ores and this process is also the same which involves the refining of ores or alloyed noble metals like gold and silver from base metals such as zinc, copper, arsenic etc. which are present in the ores. These ores are treated under extremely high temperatures thereby separating the metals as they are considered to not get oxidised. So we can say that (iii) silver is purified by cupellation.
Lastly the distillation process which involves separation of components of a mixture on the basis of their boiling points. Similarly, mercury is extracted from its ore using this process where the sulphide ore is heated in the presence of oxygen at a temperature above its melting point so that the oxygen combines with sulphur and results in the formation of sulphur dioxide and giving the pure metal form.

So the correct answer is (D):

The mineral carnallite contains ___Magnesium___and__Potassium___metals.Silver is purified by cupellation and Mercury is purified by distillation.

Note: Carnallite has different colour combinations like it can be yellow to red, reddish to colourless or blue in colour. It can be produced by grinding the magnesium chloride and potassium chloride combinations of these hydrates.