When water is added gradually to a white solid X, a hissing sound is heard and a lot of heat is produced forming a product Y. A suspension of Y in water is applied to the walls of a house during white washing. A clear solution of Y is also used for testing carbon dioxide gas in the laboratory.
(a) What could be solid X? Write its chemical formula.
(b) What could be product Y? Write its chemical formula.
(c) What is the common name of the solution of Y which is used for testing carbon dioxide gas?
(d) Write chemical equation of the reaction which takes place on adding water to slid X.
(e) Which characteristic of chemical reactions is illustrated by this example?

Open in App

Solution

(a) Solid X is calcium oxide, commonly known as quicklime. Its chemical formula is CaO.

(b) Product Y is calcium hydroxide, commonly known as slaked lime. Its chemical formula is Ca(OH)₂.

(c) Common name of the solution of Y is "lime water", which is used to test carbon dioxide gas.

(d) CaO (s) + H₂O (l) $\to$ Ca(OH)₂ (aq) + HEAT

(e) This chemical reaction is characterised by change in temperature because a huge amount of heat is evolved in this reaction, causing rise in temperature of the mixture.

Suggest Corrections

Similar questions

Q. On adding a white solid ‘X’ to water, a hissing sound is heard and a lot of heat is produced along with the formation a product ‘Y’.
The solution of ‘Y’ is applied on the walls of buildings during whitewashing. It reacts with carbon dioxide in air to form 'Z'. This Z gives a shiny finishing to the walls after 2-3 days of whitewashing.

(ii) The chemical formula of the product Y is _______.

Q. On adding a white solid ‘X’ to water, a hissing sound is heard and a lot of heat is produced along with the formation a product ‘Y’.
The solution of ‘Y’ is applied on the walls of buildings during whitewashing. It reacts with carbon dioxide in air to form 'Z'. This Z gives a shiny finishing to the walls after 2-3 days of whitewashing.

(i) The chemical formula of solid ‘X’ is _______.

Q. On adding a white solid ‘X’ to water, a hissing sound is heard and a lot of heat is produced along with the formation a product ‘Y’.
The solution of ‘Y’ is applied on the walls of buildings during whitewashing. It reacts with carbon dioxide in air to form 'Z'. This Z gives a shiny finishing to the walls after 2-3 days of whitewashing.

(iii) Formation of Y in this case is an example of _________ reaction.

Q. When the solution of substance X is added to a solution of potassium iodide, then a yellow solid separates out from the solution.
(a) What do you think substance X is likely to be?
(b) Name the substance which the yellow solid consists of.
(c) Which characteristic of chemical reaction is illustrated by this example?
(d) Write a balanced chemical equation for the reaction which takes place. Mention the physical states of all the reactants and products involved in the chemical equation.

When the solution of substance X is added to a solution of potassium iodide, then a yellow solid separates out from the solution.

(a) What do you think substance X is likely to be ?

(b) Name the substance which the yellow solid consists of.

(c) Which characteristic of chemical reactions is illustrated by this example ?
(d) Write a balance chemical equation for the reaction which takes place. Mention the physical states of all the reactants adn products involved in the chemical equatio.

Join BYJU'S Learning Program