JEE Main201912 Apr 2019Evening ShiftChemistryd and f Block ElementsActual
Thermal decomposition of a Mn compound X at 513 K results in compound Y , M n O 2 and a gaseous product. M n O 2 reacts with N a C l and concentrated H 2 S O 4 to give a pungent gas Z . X , Y and Z , respectively, are:
Options
- AK 3 M n O 4 , K 3 M n O 4 and C l 2
- BK 2 M n O 4 , K M n O 4 and C l 2
- CK 2 M n O 4 , K M n O 4 and S O 2
- DK M n O 4 , K 2 M n O 4 and C l 2
Correct answer
D. K M n O 4 , K 2 M n O 4 and C l 2
Step-by-step solution
Potassium manganate is water soluble and so is leached out as green filtrate. MnO 2 is insoluble in water and gives black residue. The oxygen gas is released in this reaction. In the first step potassium permanganate ( KMnO 4 ) the compound (X) decomposes on heating to give potassium manganate ( K 2 MnO 4 ) which is the compound (Y), MnO 2   and the gaseous product is oxygen. In the second step MnO 2 further reacts with NaCl and concentrated sulfuric acid to give a pungent-smelling gas that is Chlorine gas ( C