Question

Assertion: In the froth floatation process, sodium ethyl xanthate is used as collector.
Reason: Sulfide ores are water soluble
A.Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
B.Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
C.Assertion is correct but Reason is incorrect.
D.Assertion is incorrect and Reason is correct.

Answer 1

Hint: We have to know that Froth flotation is a process for separating hydrophobic materials from hydrophobic. Sulphide ores of copper, zinc and lead are concentrated by this.

Complete step by step answer:
We can say the principle of froth floatation is that sulphide ores are wetted using pine oil, but the gangue particles are wetted by water.
We can add collectors to increase the non-wettability of the mineral particles. Some of the examples of collectors are pine oil, fatty acids and xanthates.
The froth is stabilized using the froth stabilizers. Some of the examples of froth stabilisers are cresols, and aniline.
If two sulphide ores are present, then we can separate the two sulphide ores by adjusting the proportion of oil to water or by adding depressants.
We have to blow a strong current of air through the suspension. It produces a heavy froth or foam on the surface. The metal sulphide is wetted by the oil whereas the gangues is not and the sulphide-oil mixture is brought to the surface with the help films of oil The froth is removed off, the gangue would settle at the bottom or remains under the froth. By this flotation method, we can concentrate over \[90\% \] of a sulphide ore to 1/10 of its original bulk.
During the flotation process of some ores, these substances (pine oil and turpentine oil) are added which activate or depress the flotation property of the minerals and thus help in the separation of minerals present in the ore. For example, galena $\left( {PbS} \right)$is usually related with sphalerite \[\left( {ZnS} \right)\] and pyrites\[\left( {NaCN} \right)\].
The assertion in the process of froth flotation, we can use sodium ethyl xanthate is true nut the reason sulfide ores are water-soluble is false because ores of sulfide is insoluble in water.
Assertion is correct but Reason is incorrect.

So, the correct answer is Option C .

Note:
 We have to know that pH is an essential factor in floatation. A mild change in the pH would result in the productivity loss and efficiency of the operation. We can use Lime, sodium hydroxide, sodium carbonate to contain the basic nature of the slurry and acids like sulfurous acid and sulfuric acid are used to maintain the acidic medium.