Chemistry
| BASES — Ions present in bases | |
|---|---|
| a. Alkali — dissociates yielding hydroxyl ions | |
| 16. Sodium hydroxide | NaOH [aq.] ⇌ …………… + …………… |
| 17. Ammonium hydroxide | NH4OH [aq.] ⇌ …………… + …………… |
| b. Classification | |
| 18. Monoacidic base [Acidity = 1 ] | KOH [aq.] ⇌ …………… + …………… |
| 19. Diacidic base [Acidity = 2] | Cu(OH)2 [aq.] ⇌ …………… + …………… |
| c. Preparation of bases | |
| 20. From metals | Na + O2 ⟶ …………… |
| 21. From metallic oxides and metals | K2O + H2O ⟶ …………… |
| K + H2O ⟶ …………… + …………… | |
| 22.From salts | AlCl3 + NaOH ⟶ …………… + …………… ↓ |
| FeSO4 + NaOH ⟶ …………… + …………… ↓ | |
| 23. By thermal decomposition | ZnCO3 ⟶ …………… + …………… [g] |
| Pb(NO3)2 ⟶ …………… + ……………[g] + ………….. [g] | |
| c. Properties of bases | |
| 24. Neutralizes acids | PbO + HNO3 ⟶ …………… + …………… |
| Fe(OH)2 + HCl ⟶ …………… + …………… | |
| Reaction with | |
| 25. Metallic salt solution | CuCl2 + NaOH ⟶ …………… + …………… ↓ |
| FeCl3 + NaOH ⟶ …………… + …………… ↓ | |
| 26. Ammonium salts | NH4Cl + NaOH ⟶ …………… + …………… + …………… [g] |
| NH4Cl + Ca(OH)2 ⟶ …………… + …………… + …………… [g] |
Answer
| BASES — Ions present in bases | |
|---|---|
| a. Alkali — dissociates yielding hydroxyl ions | |
| 16. Sodium hydroxide | NaOH [aq.] ⇌ Na+ + OH- |
| 17. Ammonium hydroxide | NH4OH [aq.] ⇌ NH4+ + OH- |
| b. Classification | |
| 18. Monoacidic base [Acidity = 1 ] | KOH [aq.] ⇌ K+ + OH- |
| 19. Diacidic base [Acidity = 2] | Cu(OH)2 [aq.] ⇌ Cu2+ + 2OH- |
| c. Preparation of bases | |
| 20. From metals | 4Na + O2 ⟶ 2Na2O |
| 21. From metallic oxides and metals | K2O + H2O ⟶ 2KOH |
| 2K + 2H2O ⟶ 2KOH + H2 | |
| 22. From salts | AlCl3 + 3NaOH ⟶ 3NaCl + Al(OH)3 ↓ |
| FeSO4 + 2NaOH ⟶ Na2SO4 + Fe(OH)2 ↓ | |
| 23. By thermal decomposition | ZnCO3 ⟶ ZnO + CO2 [g] |
| 2Pb(NO3)2 ⟶ 2PbO + 4NO2 [g] + O2 [g] | |
| c. Properties of bases | |
| 24. Neutralizes acids | PbO + 2HNO3 ⟶ Pb(NO3)2 + H2O |
| Fe(OH)2 + 2HCl ⟶ FeCl2 + 2H2O | |
| Reaction with | |
| 25. Metallic salt solution | CuCl2 + 2NaOH ⟶ 2NaCl + Cu(OH)2 ↓ |
| FeCl3 + 3NaOH ⟶ 3NaCl + Fe(OH)3 ↓ | |
| 26. Ammonium salts | NH4Cl + NaOH ⟶ NaCl + H2O + NH3 [g] |
| 2NH4Cl + Ca(OH)2 ⟶ CaCl2 + 2H2O + 2NH3 [g] |
Related Questions
ACIDS — Ions present in acids Complete and balance the equations a. Definition — Dissolves in water yielding hydronium ions 1. Hydrochloric acid HCl ⇌ …………… + Cl-
[H+ + H2O ⇌ …………… ]
HCl + H2O ⇌ …………… + ……………2. Nitric acid HNO3 + H2O ⇌ …………… + …………… 3. Sulphuric acid H2SO4 + H2O ⇌ …………… + …………… b. Classification 4. Monobasic acid [Basicity = 1 ] HCl [aq.] ⇌ …………… + …………… 5. Dibasic acid [Basicity = 2] H2SO4 [aq.] ⇌ …………… + …………… 6. Tribasic acid [Basicity = 3] H3PO4 [aq.] ⇌ …………… + …………… c. Preparation of acids 7. From non-metals H2 + Cl2 ⟶ …………… 8. From acidic oxides CO2 + H2O ⟶ …………… SO3 + H2O ⟶ …………… P2O5 + H2O ⟶ …………… 9. From normal salts KNO3 + H2SO4 ⟶ …………… + …………… NaCl+ H2SO4 ⟶ …………… + …………… 10. By oxidation of non-metals S + HNO3 ⟶ …………… + H2O …………… [g] d. Properties of acids 11. Neutralizes bases CuO + H2SO4 ⟶ …………… + …………… NaOH + HCl ⟶ …………… + …………… Reaction with 12. Chlorides and nitrates NaCl + H2SO4[conc.] ⟶ …………… + …………… NaNO3 + H2SO4[conc.] ⟶ …………… + …………… 13. Carbonates and bicarbonates Na2CO3 + H2SO4 ⟶ …………… + H2O + …………… [g] NaHCO3 + H2SO4 ⟶ …………… + H2O + …………… [g] 14. Sulphites and bisulphites Na2SO3 + HCl ⟶ …………… + H2O + …………… [g] NaHSO3 + HCl ⟶ …………… + H2O + …………… [g] 15. Active metals Zn + HCl ⟶ …………… + …………… [g] SALTS — Ions present in salts 27a. Normal salt [formation] NaOH [excess] + H2SO4 ⟶ …………… + H2O 27b. Acid salt [formation] NaOH [insufficient] + H2SO4 ⟶ …………… + H2O Preparation of salts — General methods Direct combination — Synthesis 28. Iron and Chloride — salt iron [III] Chloride Fe + Cl2 ⟶ …………… 29. Zinc and sulphur — salt zinc sulphide Zn + S ⟶ …………… Displacement — Action of dilute acid on active metals 30. Iron — salt iron [II] sulphate Fe + H2SO4 ⟶ …………… + …………… [g] 31. Zinc — salt zinc sulphate Zn + H2SO4 ⟶ …………… + …………… [g] 32. Magnesium — salt magnesium chloride Mg + HCl ⟶ …………… + …………… [g] Precipitation — by double decomposition of two salt solutions 33. Lead nitrate and sodium chloride Pb(NO3)2 + NaCl ⟶ …………… + …………… ↓ 34. Calcium chloride and sodium carbonate CaCl2 + Na2CO3 ⟶ …………… + …………… ↓ Neutralization — Action of dilute acid on insoluble base 35. Oxide — salt copper sulphate CuO + H2SO4 ⟶ …………… + …………… 36. Hydroxide — salt copper sulphate Cu(OH)2 + H2SO4 ⟶ …………… + …………… Neutralization — [Titration] Action of dilute acid on an alkali 37. Hydroxide — salt sodium chloride NaOH + HCl ⟶ …………… + …………… 38. Hydroxide — salt ammonium chloride NH4OH + HCl ⟶ …………… + …………… Action of dilute acid on carbonate & bicarbonate 39. Carbonate — salt lead nitrate PbCO3 + HNO3 ⟶ …………… + …………… + …………… [g] 40. Carbonate — salt copper chloride CuCO3 + HCl ⟶ …………… + …………… + …………… [g] 41. Bicarbonate — salt potassium sulphate KHCO3 + H2SO4 ⟶ …………… + …………… + …………… [g] Mention the colour changes observed when the following indicators are added to acids:
(i) Alkaline phenolphthalein solution.
(ii) Methyl orange solution
(iii) Neutral litmus solution
Which of the following hydroxides is not an alkali — [Choose from the choices A, B, C and D]
(A) ammonium hydroxide
(B) calcium hydroxide
(C) copper hydroxide
(D) sodium hydroxide