BSEB 12th Chemistry Top 20 Short Type Question With Answer On New Pattern Model Set Question

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12th Chemistry Most VVI Subjective Short Type Question इन्टर परीक्षा Chemistry रसायन  विज्ञान लघु उत्तरीय प्रशन

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Class 12th Board Exam Chemistry Most VVI Short Type VVI Guess Question for Board Exam | 12th Board Exam Chemistry Question Short & Long Type Question With Answer, 12th Board Exam Chemistry Short Long Type VVI Guess Question Inter Chemistry top 20 Short Question

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Short Type Question in English

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👉 Question With Answer In Hindi Language – CLICK HERE 

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1. Explain why H₂O is in liquid state while H₂S is in gaseous state at room condition.” 

Ans. H—O bond is more polar than H—S bond because of greater electronegativity difference in the bonding atoms. As a result, H₂O molecules are involved in the intermolecular hydrogen bonding and get associated to be liquid at room temperature. Since intermolecular hydrogen bonding is negligible in the molecules of H₂S, they do not get associated and remain in the gaseous state at room temperature.

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2. What is carbocation ? Explain. 

Ans. Carbocation : A carbocation is an ion with positively charged carbon atom. Among the simplest example methenium CH₃⁺; ethanium C₂H₇⁺ Some carbocations may have twoor more positive charges, on the same carbon atom or on different atom such as ethylene dictation (C₂H₄⁺). It is classified in two catagories according to the valence of the charged carbon.

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3. What do you mean by acid rain? Explain. 

Ans. Acid rain :- It is a rain or any other form of precipitation that usually acidic meaning that it possesses ‘elevated levels – hydrogen ions (low pH). It can have harmful effects on plant aquatic animals and infrastructure. Acid rain is caused by emission of atmosphere to produce acids. In chemical acid rain can cause point to peel, corrosion of steel structures as bridges and erosion of stone statues.

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4. What is salt bridge? What are its uses? 

Ans. Salt bridge:- In electrochemisty, it is a laboratory device used to connect the oxidation and reduction half-cells of a galvanic.. cell (voltaic cell, a type of electrochemical cell. Salt bridge usually .. comes into two types : glass tube and filter paper. 

Uses :- It is used in voltaic cell. Purpose of salt bridge is only to move electrons from electrotype solution to the other. 

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5. Describe the principle of extraction of aluminium metal. 

Ans. Extraction of aluminium from bauxite involves two steps— (a) Purification of bauxite. (b) Electrolysis of pure alumina. 

(a) Purification of bauxite : Bauxite is treated with a hot concentrated (45°C) solution of sodium hydroxide. 

(b) Electrolysis of pure alumina: Pure alumina is dissolved in molten cryolite (Na₃Alf₆) and is electrolysed in an iron tank linked inside with carbon. Carbon lining serves as cathode while a number of carbon rods dipping in the fused electrolyte. Serve as anode. The temperature of the electrolyte is maintained between 1200 – 1300 K. 

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6. What is analgesics? 

Ans. Analgesics :- The chemical which are used to relieve the pain are known as analgesics. They may be of two types : (a) Non-narcotics. Examples : Aspirin. (b) Narcotics (included sleep and unconsciousness) Example : Morphine.

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7. What is antibiotics? 

Ans. Antibiotics :- The substances which are produced by certain macro organisms (fungi, bacteria and moulds) and use to inhibit the growth or to kill the micro organism are known as antibiotics. Examples : Penicilin.

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8. What is antacids ? 

Ans. Antiacids:- The drugs used to cure such burning sensation produced by taking spicy and oily food by humans are known as antiacids.

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9. Describe Faraday’s laws of electrolysis. 

Ans. Faraday’s laws of electrolysis : Faraday in the year (1833) quantitatively studied the phenomenon of electrolysis and he put forward the following two laws of electrolysis. 

(i) Faraday’s first law of electrolysis : The quantity of a substance obtained in electrolysis is proportional to the auantity of electricity passed through its electrolyte. 

Example : Dissolve or dispointed amount of substance 

m∝ It or, m = ZIt (where Z= electrochemical equivalent) 

(ii) araday’s Second law of electrolysis : The quantities of different substances liberated by passage of same quantity of electricity through different electrolytes are proportional to their chemical equivalents (E). Example, m ∝ E

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10. How will you distinguish between Lyophobic colloid and Lyophilic colloids? 

Ans. Distinguish between Lyophobic colloid and Lyophilic colloids :-

	Lyophobic colloid	Lyophilic colloids
i	They are easily precipitated by adition of  a small amount of suitable electrolyte.	They are quite stable and are not easily precipited or   coagulated.
ii	They are irreversible in nature	They are reversible in nature.
iii	Their viscosity is almost the same as that of the medium.	Their velocity is much higher  than that of medium.
iv	Their surface tension is nearly same as that of the dispersion medium.	Their surface tension is usually lower than that of the dispersion medium.

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11. The boiling point of ether is much lower than that of alcohol, why? 

Ans. Boiling point of ether is less than alcohol. There is no co-operation between the molecules of alcohol because hydrogen bond is present in it. There is no ihydrogen bond between the molecules of ether. 

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12. Phenol is more acidic than alcohol, How? 

Ans. Phenol is a weak acid. It has acidic property because it give phenoxide ion is the solution.

C₆H₅OH + H₂O —> C₆H₅O^– + H₃O^–

Negative sign dispersed on the whole benzenering. This charge give stability to the phenoxide ion. Due to this, it is acidic. 

Alcohol is less acidic than phenol because +1 effect is present on alkyl radical in alcohol. 

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13. Mention one use each of the following: 

(a) Paracetamol      (b) Tincture of iodine. 

Ans. (a) Paracetamol— It reduces the temperature of the human body in the period of high fever. 

(b) Tincture of iodine— It is a dilute solution of iodine perepared in ethanol (2 to 3%). This chemical prevent the growth of micro-organisms and may also kill them.

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14. Write IUPAC names of the following complex compounds 

(i) K₄Fe(CN)₆   (ii) [Cu(NH₃)₄](NO₃)₂  (iii) Li[A1H₄] 

Ans.-  (1) Potassium ferrocyanide 

(ii) tetra amoniacopper (II) nitrate

(iii) lithiumtetrahydroaluminate (III). 

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15. Differentiate between roasting and calcination-

Ans. Roasting :- The method of change of oxide molecule is heated present of a presence of air sulphite aur carbonet is called roasting. 

Calcination :- The method of change of oxide molecule is heated in the absence of air sulphite or carbonate is called calcination. The difference between Roasting and Calcination can be mention as follows 

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16. What is reverse osmosis ?

Ans. Reverse osmosis :- If external pressure greater than osmotic pressure applied on solution, the flow of solvent molecules can be made proceed from the solution towards pure solvent. This type of osmosis is termed as reverse osmosis. Reverse osmosis is used for the distilation of sea water for getting fresh drinking water.

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17. How will you distinguish between methanoic acid and ethanoic acid ? 

Ans.

	Methanoic acid	Ethanoic acid
i	It is difused Tollen’s reagent.	It is no effect on Tollen’s reagent.
ii	It is difused Fehling’s solution.	It is no effect on Fehling’s solution

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18. What are Enzymes ? 

Ans.:- Enzymes are proteins that catalyse biological reactions. They are very specific in nature and catalyse only a particular reaction for a particular substrate. Enzymes are usually named after the particular substrate or class of substrate and some times after the particular reaction.

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