Acids, Bases & Salts

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H+1 + OH-1  HOH

Acid + Base  Water + Salt (double replacement)

HCl (aq) + NaOH (aq)  HOH (l) + NaCl (aq)

H2SO4 (aq) + KOH (aq)  2 HOH (l) + K2SO4 (aq)

HBr (aq) + LiOH (aq) 

H2CrO4 (aq) + NaOH (aq) 

HNO3 (aq) + Ca(OH)2 (aq) 

H3PO4 (aq) + Mg(OH)2 (aq) 

جمعرات، 28 ربیع الثانی، 1438

Topic 10: ACIDS, BASES & SALTS

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Slide 16

Topic 10: ACIDS, BASES & SALTS

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Formation of Hydronium ion( H30+).

The hydrogen ion H+(aq) does not exist as such in aqueous solutions. Hydrogen ions combine with water molecules to give a more stable species, the hydronium ion H3O+.

HCl(aq) + H2O(l) < ========= H3O+(aq) + Cl-(aq)

Acids can contain different numbers of acidic hydrogens, and can yield different numbers of H3O+ ions in solution.

جمعرات، 28 ربیع الثانی، 1438

Slide 17

USES OF ACIDS

Topic 10: ACIDS, BASES & SALTS

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HCl in stomach

H2SO4 in car batteries, as drying agent’

HNO3 in manufacturing of fertilizers

Ethanoic acid in food industry

Fatty acids in soap making

Ascorbic acid in medicine

جمعرات، 28 ربیع الثانی، 1438

Slide 18

Chemical Properties of Bases

Topic 10: ACIDS, BASES & SALTS

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Neutralisation.

Ammonium salts are decomposed when mixed with a base eg sodium hydroxide. The ammonia is readily detected by its pungent odour (strong smell) and by turning damp red litmus blue.

NaOH + NH4Cl ==> NaCl + H2O + NH3

Ionically: NH4+ + OH- ==> H2O + NH3

This reaction can be used to prepare ammonia gas and as a test for an ammonium salt.

جمعرات، 28 ربیع الثانی، 1438

Slide 19

Topic 10: ACIDS, BASES & SALTS

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Chemical Properties of Bases

Alkali's are used to produce the insoluble hydroxide precipitates of many metal ions from their soluble salt solutions.

2NaOH(aq) + CuSO4(aq) ==> Na2SO4(aq) + Cu(OH)2(s)

ionically: Cu2+(aq) + 2OH-(aq) ==> Cu(OH)2(s)

This reaction can be used as a simple test to help identify certain metal ions.

جمعرات، 28 ربیع الثانی، 1438