Question

A water insoluble substance X‘on reacting with dilute H2SO4 released a colourless and odourless gas accompanied by brisk effervescence. When the gas was passed through water, the solution obtained turn blue litmus red. On bubbling the gas through lime water, it initially became milky and the milkiness disappeared when the gas was passed in excess. Identify the substance X and write the chemical equations of the reaction involved. ​

Answer 1

$\rm{Answer:}$

✒ Insoluble substance X is $\bold{CaCO_3}$ (calcium carbonate/limestone).

✒ Reactions:-

• $\bold{CaCO_{3(s)}+H_2SO_{4(aq)}\longrightarrow{}CaSO_{4(aq)}+CO_{2(g)}+H_2O_{(l)}}$

– $\bold{CO_2}$ is the colourless & odourless gas evolved

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• $\bold{CO_{2(g)}+H_2O_{(l)}\longrightarrow{}H_2CO_{3(aq)}}$

– The evolved gas reacts with water to produce $\bold{H_2CO_3}$ which is acidic and turns blue litmus red.

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• $\bold{Ca(OH)_{2(aq)}+CO_{2(g)}\longrightarrow{}CaCO_{3(s)}+H_2O_{(l)}}$

– Lime water reacts with the evolved gas to produce $\bold{CaCO_3}$ (a white precipitate) which is responsible for the milkness of the solution.

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• $\bold{CaCO_{3(s)}+H_2O_{(l)}+CO_{2(g)}\longrightarrow{}Ca(HCO_3)_{2(aq)}}$

– On passing excess carbon dioxide(evolved gas) the milkness disappears due to the formation of a water soluble product - calcium bicarbonate.

Answer 2

Answer:

CHEMISTRY

A solution is defined as a:

A .

Homogeneous mixture of two or more substances

B .

Heterogeneous mixture of two or more substances

C .

Homogeneous mixture of liquid and solid components only

D .

Homogeneous mixture consisting of water as one of the

A solution is a homogeneous mixture of two or more substances. A solution may exist in any phase. 

A solution consists of a solute and a solvent. 

The solute is the substance that is dissolved in the solvent.

For example, in a saline solution, salt is the solute dissolved in water as the solvent.