Question

Assertion :Van-Arkel method is used to prepare samples of some metals. Reason: It involves the reaction of CO with metals to form volatile carbonyls that decompose on heating to give pure metal.

Read the above assertion and reason and choose the correct option regarding it.

• 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

The correct option is C Assertion is correct but Reason is incorrect

Van-Arkel method :

Crude metal is heated with a suitable substance so that the pure metal present in it may be converted into stable volatile compound leaving behind impurities. The compound so formed is then decomposed by heating to get the pure metal. Van Arkels method is used to purify crude titanium metal. It is heated with iodine to about 500K to form a volatile compound. $Ti{I}_4$ leaving behind the impurities .$Ti{I}_4$ is further heated to 1700K when it decomposes to give pure titanium.

van-Arkel method involes use of $I_2$ to form volatile iodide of metals which on decomposition gives pure metals.