RRB JE Electrical question paper with solution 2013 | RRB JE Electrical

Ques.41. Which oxide of nitrogen is formed when ammonium nitrate is heated?

  1. NO
  2. NO2
  3. N2O
  4. O2

Answer.3. N2O

Explanation:-

When ammonia solution react with nitric acid, amonium nitrate is formed.

NH3 + HNO→ NH4NO3

Ammonium nitrate on heating gives the gaseous product (Nitrous oxide), therefore, no residual left behind.

NH4NO3 → N2O (Nitrous oxide) + 2H2O(Water)

 

Ques.42. The strongest reducing agent among the following acids is:-

  1. Formic Acid
  2. Acetic Acid
  3. Propionic Acid
  4. Chloro Acetic Acid

Answer.3. Propionic Acid

Explanation:-

A reducing agent (aka a reductant or reducer) is an element or compound that loses (donates) an electron.

The chemical compound propionic acid (systematically named propanoic acid) is a naturally occurring carboxylic acid with chemical formula CH3CH2COOH. In its pure state, propionic acid is a colorless, corrosive liquid with a sharp, somewhat unpleasant, odor. The anion CH3CH2COOH , as well as the salts and esters of propionic acid, are known as propionates (or propanoates).

The physical properties of propionic acid are intermediate between those of the smaller carboxylic acids, formic and acetic acids, and those of the larger fatty acids. Hence in this option, propionic acid is the strongest reducing agent.

 

Ques.43. Amino Acids are produced by the hydrolysis of

  1. Fat
  2. Carbohydrates
  3. Protein
  4. Nucleic Acid

Answer.3. Protein

Explanation:-

Hydrolysis:- Decomposition of a chemical compound by reaction with water, such as the dissociation of a dissolved salt or the catalytic conversion of starch to glucose.

Hydrolyzed protein from animals and vegetable is called peptone. Hydrolyzed proteins provide peptides, polypeptides, proteases, amino acids, carbohydrates, various inorganic and organic micronutrients and essential minerals.

 

Ques.44. Electrolysis of an aqueous solution of sodium succinate gives:-

  1. C2H6
  2. C2H2
  3. C2H4
  4. C3H6

Answer.2. C2H2

Explanation:-

When an aqueous solution of sodium or potassium salt of a dibasic acid (i.e. sodium succinate) is electrolyzed, an alkene (ethylene) is produced.

 

Ques.45. Which of the following electrolyte is least effective in causing coagulation of ferric hydroxide solution?

  1. KCl
  2. K2SO4
  3. K2CrO4
  4. K3[Fe(CN)6]

Answer.1. KCl

Explanation:-

Lyophilic sole:- The word lyophilic means solvent loving. Substances, like gum, starch, gelatin and agar-agar, KCL etc. when mixed with a suitable liquid like water readily form the colloidal sol, are called lyophilic or hydrophilic and the colloidal sol thus obtained is called lyophilic or hydrophilic sol. As they form the sol directly they are also called intrinsic colloids.

If the dispersed phase is separated from the dispersion medium, say by evaporation, the sol can be obtained again by simply remixing it with the dispersion medium. Therefore, these sols are also called reversible sols. Further, this type of sols are quite stable and they are not easily precipitated or coagulated. Their stability is due to their high degree of hydration.

Since KCL is lyophilic hence it is not easy to coagulate the KCL with other substance.

Lyophobic sol:- The word lyophobic means solvent hating. Metals, their oxides and sulphides etc. when simply mixed with the dispersion medium, say water, do not form a colloidal sol. Special methods are employed to prepare their sols. Such substances are called lyophobic and the sol obtained is called lyophobic or hydrophobic sol. As their sols are obtained by indirect methods, these are called extrinsic colloids.

 

Ques.46. Which of the following solutions of NaCl has the lowest value of specific conductance?

  1. 1 M
  2. 0.1 M
  3. 0.01 M
  4. 0.001 M

Answer.4. 1 M

Explanation:-

Equivalent conductance Υ = k × 100/Molarity

Since from the above equation it is clear that the conductance is inversely proportional to the molarity hence when the molarity increases the conductance decreases.

 

Ques.47. Number of ions present in K4[Fe(CN)6] is

  1. 2
  2. 5
  3. 3
  4. 4

Answer.2.4

Explanation:-

The ions present in aq solution of K4[Fe(CN)6] (Potassiumhexacyanoferrate) is

Potassium(K) has a +1 charge there are 4 ion therefore total ion will be 4K+

Iron (F)e has +2 oxidation state where as Cynaide (CN) has -1 thus +2 – 6 = –4

Hence ions present is 4K+ and [Fe(CN)6]–4

 

Ques.48. Soda ash is-

  1. Na2CO3
  2. Na2CO3.H2O
  3. Na2CO3.7H2O
  4. Na2CO3.10H2O

Answer.1. Na2CO3

Explanation:-

Some salts that do not contain hydroxide ion produce this ion in solution. The most widely used of these is sodium carbonate, Na2CO3, which is commonly known as soda ash. 

 

Ques.49. An aqueous solution of CuSO4 changes blue litmus to red due to

  1. Cu+2 ions present
  2. SO4−2 ions present
  3. Reduction taking Place
  4. Hydrolysis taking place

Answer.1. Cu+2 ions present

Explanation:-

‘CuSO4 ‘ is acidic in aqueous solution as it turns blue litmus red. It is salt of the strong acid (H2SO4) and a weak base(CuOH). It forms H+ ions which are more than OH ions. The process is called hydrolysis.

 

Ques.50. Of the following an amphoteric hydroxide is

  1. Ca(OH)2
  2. NaOH
  3. Cu(OH)2
  4. Zn(OH)2

Answer.4. Zn(OH)2

Explanation:-

An amphoteric hydroxide is a metal hydroxide that reacts with both bases and acids. Zinc is an example of a metal that forms such a hydroxide. Zinc hydroxide, Zn(OH)2, is an insoluble hydroxide, as are most of the metal hydroxides except those of Groups IA and IIA elements. 

With acid

Zn(OH)+ 2H3O → ZN2 + 4H2O

With base

Zn(OH)+ 2OH– → Zn(OH)42−

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