What happens when dilute hydrochloric acid is added to the following and write balanced chemical equations:

i. Bleaching powder


ii. Zinc granules


iii. Baking soda


OR


You have two solutions A and B. The pH of the solution A is 6 and pH of solution B is 8. Which solution has more hydrogen ion concentration? Which of these is acidic and which one is basic?

i. Bleaching Powder is calcium Oxychloride. The chemical formula of bleaching powder is CaOCl2.


Bleaching powder reacts with dilute HCl to liberate Cl2 gas, water and Calcium Chloride.


CaOCl2(s) + 2HCl (aq) CaCl2(s) +Cl2 (g) +H2O (l)


ii. When dilute hydrochloric acid is poured on zinc granules, then zinc sulphate is formed along with the evolution of a gas. Zinc is more reactive than hydrogen, so displaced it from hydrochloric acid.


The gas evolved is hydrogen. We can test its presence by bringing a burning candle near the mouth of the test tube and hearing for a popping sound. Only hydrogen gas burns with a 'pop' sound.


2HCl (aq) + Zn (s) ZnCl2 (aq) + H2 (g)


iii. Mixing baking soda, or NaHCO3, with hydrochloric acid, or HCl, results in table salt, NaCl, as well as water, H2O, and carbon dioxide, CO2. These experiments can also demonstrate stoichiometry, which deals with the reactants and products in chemical reactions.”


NaHCO3(s) + 2HCl (aq) NaCl(s) + H2O (l) + CO2 (g)


This is a neutralization reaction it releases bubbles of carbon dioxide gas


OR


The character of acidic, basic and neutral is defined by the concentration of hydrogen ions [H+](mol/L). A solution with a concentration of hydrogen ions higher than 10-7mol/L is acidic, and a solution with a lower concentration is alkaline.


Using the formula,


pH=-log [H+],


a pH of 7 is neutral, a pH less than 7 is acidic, and a pH greater than 7 is basic. As one can see from this formula, ten times a given concentration of hydrogen ions means one unit lower in terms of pH value (higher acidity), and vice versa.


The pH value of a solution varies from 0 to 14. The pH value is 0 for a very strong acid and the pH value is 14 for a very strong base. The pH value is 7 for a neutral solution. Hence A is acidic and B is basic in nature.


The concentration of hydrogen ion decreases from pH value of 0 to 14 therefore A has more hydrogen ion concentration.


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