Question

A student dropped a few pieces of marble in dilute HCL contained in a test tube. the gas evolved was passed through lime water. what change would be observed in lime water? write chemical reactions for both the changes observed.

Answer 1

The gas formed is Carbon dioxide.

Lime water turns milky when you pass carbon dioxide through it because a reaction that produces a white precipitate takes place.

When you pass carbon dioxide through this solution, the two compounds carbon dioxide (CO2) and calcium hydroxide (CaOH2) will react to form white and insoluble calcium carbonate which precipitates out of the solution. The reaction is as follows:

Ca(OH)2(aq) + Lime water turns milky when you pass carbon dioxide through it because a reaction that produces a white precipitate takes place.

When you pass carbon dioxide through this solution, the two compounds carbon dioxide (CO2) and calcium hydroxide (CaOH2) will react to form white and insoluble calcium carbonate which precipitates out of the solution. The reaction is as follows:

Ca(OH)2(aq) + CO2(g) →CaCO3(s)↓+H2O