Question

Consider the decomposition reaction represented above.
Which of the following reaction equations would fit this decompostion?

• A. $KCl{O}_3\to KCl+3O_2$
• B. $Mg(Cl{O}_3{)}_2\to MgC{l}_2+3O_2$
• C. $Mg(Cl{O}_3{)}_2\to Mg{O}_2+3C{l}_2$
• D. $Pb(C{O}_3{)}_2\to Pb{O}_2+3C{O}_2$

Answer 1

The correct option is B $Mg(Cl{O}_3{)}_2\to MgC{l}_2+3O_2$

In the given image, on the reactant side there are 9 atoms out of which 6 are red, 2 are blue and 1 is black which represents that 6 atoms are of the same type, 2 are of another type and 1 atom is of a different type.

• In option A, the reactant KClO₃ has only 5 atoms. Hence, it is not the correct option.
  

• In option D, both the products contain two different atoms (Pb,O and C,O) but in the image given above one of the products contain 6 atoms of the same type (red coloured atoms). Hence, option D is incorrect.
  

• In the option C, total number Cl atom on the reactant side is 2 but on the product side is 6 which is not possible. Hence, option C is also incorrect.
  

• Option B is correct in which Mg, Cl and O represent the black, blue and red coloured atoms respectively.