X is a substance which liberates CO2 on treatment with concentrated H2SO4. A warm solution of X can decolorize acidified KMnO4. X is
Answer Details
It should be noted that for X to liberate CO2, X must be a carbonate or an oxalate. Since X decolorizes KMnO4, X must be an oxalate. Therefore, X is H2C2O4.