Chemistry
Differentiate between
(i) Electrolytes and Non-electrolytes
(ii) Strong and Weak electrolytes
(iii) Anode and Cathode
(iv) Electrolytic dissociation and ionization with suitable examples.
Answer
(i) Differences between Electrolytes and Non-electrolytes are:
| Electrolytes | Non-electrolytes |
|---|---|
| Chemical compound which conduct electricity in the fused or in aqueous solution state and undergo chemical decomposition due to the flow of current through it. | Chemical compound which do not conduct electricity in the fused or aqueous solution state and do not undergo chemical decomposition due to the flow of current through it. |
| Electrolytes are ionic compounds | Non-electrolytes are covalent compounds |
| Particles in Electrolytes – ions only or Ions and molecules only | Particles in non-electrolytes – Molecules only |
| Examples : Acids — dil. HCl, HNO3 H2SO4. Alkalis — KOH, NaOH solutions. Ionic salts — PbBr2 [molten], CuSO4 [aq.] | Examples : Pure or distilled water, Alcohol, Kerosene, Carbon disulphide, liquid carbon tetrachloride, sucrose, glucose, sugar solution. |
(ii) Differences between Strong and Weak electrolytes are:
| Strong electrolytes | Weak electrolytes |
|---|---|
| They are electrolytes which allow a large amount of electricity to flow through them and hence are good conductors of electricity. | They are electrolytes which allow small amount of electricity to flow through them and hence are poor conductors of electricity. |
| They are almost completely dissociated in fused or aqueous solution state. | They are partially dissociated in fused or aqueous soln. state. |
| Particles in strong electrolytes are mainly ions only | Particles in weak electrolytes are ions and unionized molecules. |
| Examples : Generally all strong acids and bases and most salts of strong acids. Acids: dil. HCl, H2SO4, HNO3, HBr, HI. Bases : NaOH, KOH, LiOH soln. Salts: NaCl, NaNO3, Na2SO4, CuCl2 | Examples : Generally all weak acids and bases and most salts of weak acids. Acids: Carbonic, Acetic, Oxalic, Formic. Bases: NH4OH, Ca(OH)2, Mg(OH)2. Salts: Sodium carbonate, bicarbonate, oxalate and formate aq. soln. |
(iii) Differences between Anode and Cathode are:
| Anode | Cathode |
|---|---|
| It is the electrode connected to the positive terminal of the battery | It is the electrode connected to the negative terminal of the battery. |
| Anions migrate to anode | Cations migrate to cathode. |
| The anions donate excess electrons to the anode and they are oxidised to neutral atoms. Hence, Anode is the Oxidising Electrode. | The cations gain excess electrons from the cathode and they are reduced to neutral atoms. Hence, Cathode is the Reducing Electrode. |
(iv) Differences between Electrolytic dissociation and ionization are:
| Electrolytic Dissociation | Ionization |
|---|---|
| It is a process which takes place in electrovalent compounds | It is a process which takes place in covalent compounds. |
| It involves separation of ions which are already present in an ionic compounds. | It involves formation of charged ions from molecules which are not in the ionic state. |
| PbBr2 (ionic) ⇌ Pb2+ + 2Br1- | HCl [aq.] (covalent) ⇌ H1+ + Cl1-. Ionization may also involve atoms changing into ions [e.g. Mg ⟶ Mg2+ + 2e-] |
Related Questions
Compare the flow of electricity through a nickel wire and nickel sulphate solution.
Define :
(i) Electrolysis
(ii) Electrodes
(iii) Ions
(iv) Electrolytic dissociation.
State which of the following solutions are weak electrolytes — dil. HCI; carbonic acid; NH4OH; dil. H2SO4; AgNO3; Na2CO3; PbBr2; KOH; HI; oxalic acid, NaHCO3; sodium acetate; Na2SO4; NaOH.
Name three organic compounds and one neutral liquid which are non-electrolytes.