Match List – I with List – II:

Choose the correct answer from the options given below:

Correct option is A

(A) Limestone → (I) Calcium Carbonate (CaCO₃)

Limestone is a naturally occurring sedimentary rock, primarily composed of calcium carbonate (CaCO₃).

It is used as raw material in cement and lime production.

(B) Quick lime → (IV) Calcium Oxide (CaO)

When limestone is heated (calcined) at high temperature, it decomposes into quick lime (CaO) and carbon dioxide (CO₂).

Reaction:

CaCO₃ (s)→ΔCaO (s)+CO₂ (g)

(C) Slaked lime → (II) Calcium Hydroxide [Ca(OH)₂]When quick lime (CaO) is mixed with water, it produces slaked lime, chemically known as calcium hydroxide.

Reaction:

CaO (s)+H₂O (l)→Ca(OH)₂ (s)

(D) Lime water → (III) Aqueous solution of calcium hydroxide

When slaked lime is dissolved in water, the clear solution formed is called lime water.

This is an aqueous solution of Ca(OH)₂, often used to test the presence of CO₂ gas.

Information Booster:

This entire transformation forms the Lime Cycle, a fundamental process in chemistry and construction.

Lime water turns milky when CO₂ is passed through it, due to the formation of insoluble calcium carbonate:

Ca(OH)₂ (aq)+CO₂ (g)→CaCO₃ (s)+H₂O (l)

Calcium compounds are widely used in cement manufacture, whitewashing, agriculture (as soil pH corrector), and chemical industries.