Thermal Decomposition | MCQs

Explanation

Explanation

The decomposition reaction is: 

ZnCO 3(s)→ZnO(s)+CO 2(g) One mole of ZnCO₃ produces one mole of CO₂, so 10 moles will produce 10 moles of CO₂.

The molar mass of CO₂ is: 

CO₂=12+(16×2)=44g/mol Therefore, 

10 moles of CO₂=10×44=440g.

Explanation

Boric acid on heating at 100oC gives HBO2.

On heating orthoboric acid (H3BO3) at 370 K or above,

It changes to metaboric acid (HBO2).

On further heating, this yields boric oxide B2O3.

Additional information:

Orthoboric acid, $H_{3}B{O}_3$ is a white crystalline solid, with soapy touch.

It is sparingly soluble in water but highly soluble in hot water.