Question

In the contact process, sulphur trioxide is not converted to sulphuric acid by reacting it with water. Instead a two-step procedure is used. The equation for the two step involved are:
$ S{O_x} + {H_2}S{O_4} \to {H_2}{S_2}{O_y} \\
  {H_2}{S_2}{O_7} + {H_2}O \to 2{H_2}S{O_4} \\ $
Find the value of $x$and $y$:
$A)x = 2,y = 5 \\
  B)x = 3,y = 5 \\
  C)x = 2,y = 7 \\
  D)x = 3,y = 7 \\ $

Answer 1

Hint:
 Dilution of sulphur trioxide in water can yield sulphuric acid. This is really dangerous and hence not followed. The addition of sulphur trioxide to water is highly exothermic and causes the fuming of sulphuric acid. The fumes prevent the dissolution of sulphur trioxide in water.

Complete answer:
The contact interaction is the current technique for delivering sulfuric corrosive in the high fixations required for modern cycles. Platinum was at first utilized as the impurities for this response; be that as it may, as it is powerless to respond with arsenic contaminations in the sulfur feedstock, vanadium oxide is presently preferred.
The process can divided into
$ - $Combining of sulphur and oxygen to form sulphur dioxide
$ - $Extraction of sulphur
 $ - $Adding an excess of oxygen to sulphur dioxide in the presence of the catalyst vanadium pentoxide.
$ - $conversion of sulphur dioxide to sulphur trioxide.
 $ - $conversion of sulphur trioxide to sulphuric acid.
$ - $As this process is an exothermic reaction so the temperature should be as low as possible.
So the balanced reaction are shown below:
$
  S{O_3} + {H_2}S{O_4} \to {H_2}{S_2}{O_7} \\
  {H_2}{S_2}{O_7} + {H_2}O \to 2{H_2}S{O_4} $
So, the $x = 3$ and $y = 7$
So the correct answer is $(D)x = 3,y = 7$.

Note:
This incorporates the dusting tower, cooling pipes, scrubbers, drying tower, arsenic purifier and testing box. Sulfur dioxide has numerous impurities like fumes, dust particles and arsenous oxide. Accordingly, it should be decontaminated to keep away from impetus harming. In this cycle, the gas is washed with water, and dried by sulfuric corrosiveness. In the tidying tower, the sulfur dioxide is presented to a steam which eliminates the residue particles.