Question

When excess of carbon dioxide is passed through lime water, the milkiness disappears because ______.

Options

• water soluble calcium carbonate converts to water soluble calcium bicarbonate.

• insoluble calcium carbonate converts to water soluble calcium bicarbonate.

• water soluble calcium carbonate converts to insoluble calcium bicarbonate.

• insoluble calcium carbonate converts to insoluble calcium bicarbonate.

Answer 1

When excess of carbon dioxide is passed through lime water, the milkiness disappears because insoluble calcium carbonate converts to water soluble calcium bicarbonate.

Explanation:

The solution becomes milky when CO₂ is first passed through lime water because Ca(OH)₂ reacts to generate insoluble CaCO₃. When too much CO₂ is passed, the CaCO₃ dissolves and becomes soluble Ca(HCO₃)₂, which eliminates the milkiness.