Question

Assertion:
Wolframite impurities are separated from cassiterite by electromagnetic separation.
Reason:
Cassiterite being magnetic is attracted by the magnet and forms a separate heap.
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. Both Assertion and Reason are incorrect

Answer 1

Hint: The electromagnetic separation method is a method of separation of ore from the impurities present in it either magnetic or non-magnetic using an electromagnet thus, getting a pure ore at the end.

Complete step by step answer:
Before heading directly towards the assertion we first need to understand the concept of electromagnetic separation. Electromagnetic separation is the method for concentrating the ore. By the use of this method, we separate the impurities of the ore. But the essential condition is that either ore or the impurity should be magnetic. In this process, we ground the ore into small fine pieces then pass them on a conveyor belt through a magnetic roller which attracts the magnetic species and rolls down the non-magnetic species on the ground.
In the assertion statement, the impurity mentioned i.e., wolframite is a primary ore of tungsten and is magnetic with chemical formula \[\left( {FeMn} \right)W{O_4}\], whereas cassiterite is an ore of tin, and is non-magnetic with chemical formula \[Sn{O_2}\]
According to the electromagnetic separation method the non-magnetic impurity i.e., cassiterite should roll down the conveyer belt and must form a separate heap on the ground. But the reason given says quite the opposite to it that cassiterite is magnetic and thus, this statement is wrong.
Also, if we consider the electromagnetic separation method, wolframite is a magnetic impurity, which will remain attached to the conveyor belt and the non-magnetic cassiterite ore will be separated thus purifying it with the use of magnets and magnetic property of ores.

Hence, option C is the correct option. Assertion statement is true but the reason given for that is not correct.

Note: The electromagnetic separation method is generally used to concentrate sulphide minerals and the electromagnets used are advisable to be magnets of the suspended or magnetic pulley type for better and efficient separation.