Q7 of 27 Page 1

Identify the acid and base from which sodium chloride is obtained. Which type of salt is it? When is it called rock salt? How is rock salt formed?

Acid: Hydrochloric acid

Base: Sodium hydroxide


The reaction is given below:



Sodium chloride is a neutral salt.


It is called rock salt when it is found in crystalline form or like crystals and it is then mined like we mine coal.


Rock salt is formed by the crystallization of sodium chloride which is common salt. This salt is darker in colour because of impurities that are present in it. It is typically formed by the evaporation of salty water (such as seawater) which contains dissolved Na+ and Cl- ions.

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2 g of silver chloride is taken in a china dish and the china dish is placed in sunlight for some time. What will be your observation in this case? Write the chemical reaction involved in the form of a balanced chemical equation. Identify the type of chemical reaction.

OR


Identify the type of reactions taking place in each of the following cases and write the balanced chemical equation for the reactions.


(a) Zinc reacts with silver nitrate to produce zinc nitrate and silver metal


(b) Potassium iodide reacts with lead nitrate to produce potassium and lead iodide.


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Based on the group valency of elements write the molecular formula of the following compounds giving justification for each:

(i) Oxide of first group elements


(ii) Halide of the elements of group thirteen, and


(iii) Compound formed when an element, A of group 2 combines with an element, B of group seventeen.


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Write three types of blood vessels. Give one important feature of each.