Question

The following compounds have been arranged in order of their increasing stabilities. Identify the correct order.
`K_(2)CO_(3)(I),MgCO_(3)(II),CaCO_(3)(III),BeCO_(3)(IV)`
A. `I lt II lt III lt IV`
B. `IV lt II lt III lt I`
C. `IV lt II lt I lt III`
D. `II lt IV lt III lt I`

Answer 1

Correct Answer - B
`BeCO_(3) lt MgCO_(3) lt CaCO_(3) lt K_(2)CO_(3)`
Alkali metal carbonates are stable than carbonates of alkaline earth meatals, and they do not decompose on heating and their stabilities increase down the group `(darr)`, therefore potassium carbonate is thermally most stable.
`MgCO_(3)overset(Delta)(rarr)MgO+CO_(2)`