Assertion : Potassium dichromates gives deep red vapours with concentrated `H_(2)SO_(4)` and sodium chloride.
Reason : The reaction of sodium chloride with solid
`K_(2) Cr_(2) O_(7)` and concentrated `H_(2) SO_(4)` produces chromyl cholride.

Options

A. If both assetion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are ture but reason is not the correct explanation of the assertion.
C. If assertion is true but reason is false.
D. If assertion is false but reason is true.

Answer

A

Explanation

`K_(2) Cr_(2) O_(7) + 2H_(2)SO_(4) rarr KHSO_(4) + 2 CrO_(3) + H_(2) O`
`[NaC1 + H_(2)SO_(4) rarr NaHSO_(4) + HC1] xx 4`
`[CrO_(3) + 2HC1 rarr CrO_(2) C1_(2) + H_(2) O] xx 2`
`bar(K_(2) Cr_(2) O_(7) + 6 H_(2) SO_(4) + 4NaC1 rarr 2KHSO_(4) + 4 NHSOH_(4) +)`
`2 CrO_(2) C1_(2) + 3H_(2) O`
`CrO_(2) C1_(2)` (Chromy1 chloride) is liberated as deep red vapour