MCQs on Electrical Conductors, Arrhenius Theory and Ostwald's Dilution Law

Metal wires are used in electrical circuits because metals are a good conductor. An electrical conductor is a material that allows electricity to flow through it easily. Some types of materials conduct electricity more easily than others. Arrhenius was the first scientist who gave an idea of the formation of ions in solution. This idea holds good for the theory of acids and bases. Arrhenius theory also describes strong acid and weak acid. Ostwald’s Dilution Law is another well-known application of the law of mass action; the dilution law applies to dilute solutions. Ostwald published the results of his experimental tests of the expression. In experiments with over two hundred weak organic acids, he found values of k to remain constant over a wide range of dilute to moderate concentrations.

1. If a conductor length is increased, 100% then keeping all other parameters fixed, what will be the increase in power dissipate?

  1. 100%
  2. 200%
  3. 300%
  4. 400%

Answer:(b)

2. What happens to the conductivity of semiconductors when there is an increase in temperature?

  1. decrease
  2. increase
  3. first, increase and then decrease
  4. remains constant

Answer:(b)

3. Semiconductors have electrical conductivity

  1. more than metals but less than insulators
  2. less than thermistor but more than an insulator
  3. equal to the thermistor
  4. less than metals but more than typical insulators

Answer:(d)

4. When temperature increases the conductance of conductors is

  1. decrease
  2. increase
  3. first, increase and then decrease
  4. remains constant

Answer:(a)

5. When acids dissolve in water it releases

  1. H+ ion
  2. H ion
  3. H3O+ ion
  4. H3O2+ ion

Answer:(a)

6. Which element is always present in Arrhenius acid

  1. oxygen
  2. nitrogen
  3. hydrogen
  4. none of the above

Answer:(c)

7. Ostwald’s dilution law is applicable to

  1. strong electrolytes only
  2. weak electrolytes only
  3. non-electrolytes
  4. strong as well as weak electrolytes

Answer:(b)

8. In the titration of iodine against hype the indicator used is

  1. starch
  2. potassium ferricyanide
  3. methyl orange
  4. methyl red

Answer:(a)

9. According to Ostwald’s dilution law:

a. \(\alpha =\frac{\sqrt{k_{\alpha }}}{C}\)

b. \(\alpha =\sqrt{\frac{K_{\alpha }}{C}}\)

c. \(\alpha =\frac{\sqrt{k_{\alpha }}}{V}\)

d. \(\alpha =\sqrt{\frac{K_{\alpha }}{V}}\)

Answer:(b)

10. One litre of 0.5M KCl solution is electrolysed for one minute in a current of 16.08 mA. Considering 100% efficiency, the pH of the resulting solution will be

  1. 7
  2. 9
  3. 8
  4. 10

Answer:(c)

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