Question

For the series of reactions given below :

$2H_2{SO}_4\stackrel{830{}^{o}C}{\to }{2SO}_x+2H_{2}O+O_2$

$I_2+{SO}_2+{2H}_{2}O\stackrel{{120}^{o}C}{\to }zHI+H_2{SO}_4$

$2HI\stackrel{{320}^{o}C}{\to }y{I}_2+H_2$

Find the value of $x,y$ and $z$.

• A. $x=2,y=1,z=1$
• B. $x=1,y=1,z=2$
• C. $x=2,y=2,z=2$
• D. $x=2,y=1,z=2$

Answer 1

Answer: (D)

$x=2,y=1,z=2$

When sulfuric acid is heated at a higher temperature then it decomposes to sulphur dioxide.

$2H_{2}S{O}_4\stackrel{{830}^{\circ }C}{\to }2S{O}_2+2H_{2}O+O_2$.

The balanced reaction between molecular iodine and sulfur dioxide is $I_2+S{O}_2+2H_{2}O\stackrel{{120}^{\circ }C}{\to }2HI+H_{2}S{O}_4$

The balanced equation of decomposition of HI is $2HI\stackrel{{320}^{\circ }C}{\to }{H}_2+I_2$.

Therefore, $x=2,y=1,z=2.$

The correct option is $D$.