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Mixed Chemistry

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Which of the following proteins initiates the polypeptide chain?

  1. Glycine

  2. Leucine

  3. Methionine

  4. Lysine

  5. None of these


Correct Option: C
Explanation:

This option is correct because methionine amino acid is classified as non polar as it has a straight side chain that possesses a S-methyl thioether (i.e C-S-C bonding) at the gama-carbon. It is an essential amino acid in all metazoa. These are initiated by the polypeptide chain.

Which one of the following is least basic?

  1. NI3

  2. NBr3

  3. NCl3

  4. NF3

  5. None of these


Correct Option: D
Explanation:

This option is correct because the more electronegative atoms are able to remove the electron density of the nitrogen atom, making it the least basicity feature of the nitrogen halides.

Slaked lime mainly absorbs

  1. CO2

  2. NH3

  3. CO

  4. NO

  5. None of these


Correct Option: A
Explanation:

This option is correct because slaked lime are stable at ordinary condition of use and storage, but readily absorbs carbon dioxide from air to form calcium carbonate. If it is heated to decomposition to form caustic fumes of CaO, calcium hydroxide is refined from limestone.

The melting point(s) of calcium fluoride is/are

  1. 1418oC

  2. 1255oC

  3. 552oC

  4. 1477oC

  5. Both (2) and (3)


Correct Option: A
Explanation:

This option is correct because calcium fluoride is a colourless insoluble solid, the compound crystallised in cubic motif calcium cation are coordinates being centered in a box for eight fluoride ions center. Both cations and anoins are closely packed to each other due to its nature that melts at high temperature (14180C).

Which of the following is/are example(s) of pentoses?

  1. Arabinose

  2. Galactose

  3. Glucose

  4. Fructose

  5. Both (1) and (2)


Correct Option: A
Explanation:

This option is correct because arabinose is an aldopentose, a monosaccharide containing five-carbon atom and including an aldehyde functional group.

Which of the following is used as a lubricant?

  1. Asbestos

  2. Silicones

  3. Zeolites

  4. Mica

  5. None of these


Correct Option: B
Explanation:

This option is correct because the silicon base polymer is known as silicones. It provides an alternative to environment harmful hydrocarbons based products. These polymers are used in everyday items such as lubricants and cosmetics.

When sulphur is poured into a beaker of water and is crystallised into a brittle form, it is known as

  1. milk of sulphur

  2. flower of sulphur

  3. plastic sulphur

  4. colloidal sulphur

  5. None of these


Correct Option: C
Explanation:

This option is correct because when the molten sulphur is poured into a beaker of water, it forms a rubbery mass which remains in polymer form for a variable length of the time, but it may get crystallised into a brittle form.

Sucrose on acidic hydrolysis gives

  1. two glucose units

  2. glucose and galactose

  3. glucose and fructose

  4. glucose and mannose

  5. None of these


Correct Option: C
Explanation:

This option is correct because sucrose is known as cane sugar. When sucrose is hydrolysed with an acid or an enzyme, it gives an equimolar mixture of D-glucose and D-fructose.

Which one of the follwoing processes is involved in the synthesis of potassium cyanide?

  1. Acheson's process

  2. Mac-Arthur forest cyanide process

  3. Castner's process

  4. Beilby's process

  5. None of these


Correct Option: D
Explanation:

This option is correct because ammonia gas passed over the mixture of fused potassium carbonates and carbon to produce potassium cyanide, crystalline out by evaporation to obtain pure potassium cyanide.

Sodium borax is obtained by which of the following processes?

  1. Boiling finely powdered colemanite ore with sodium carbonate

  2. Dissolving finely powdered colemanite in boiling water and subsequently passing SO2 gas

  3. Direlty fusing boron with NaOH

  4. Reduction of potassium tetrafluoroborate by aluminium

  5. None of these


Correct Option: A
Explanation:

This option is correct because the finely powdered colemanite ore is usually boiled with sodium carbonate to obtain sodium borax and sodium metaborate.

Lead tree is known as

  1. (CH3COO)2Zn

  2. Pb3O4

  3. PbCO3

  4. PbO2

  5. None of these


Correct Option: A
Explanation:

This option is correct because lead is readily obtained in a crystalline state by the process of precipitation. If the Zn rod to be suspended in weak solution of lead acetate the metallic lead is thrown in a mass of arboraceous crystal known as the lead tree, it is zinc acetate.

What is produced when one mole of chlorosulphonic acid reacts with one mole of hydrogen peroxide?

  1. Caro's acid

  2. Oil of vitriol

  3. Marshall's acid

  4. Both (2) and (3)

  5. None of these


Correct Option: A
Explanation:

This option is correct because when one mole of chlorosulphunic acid reacts with one mole of hydrogen peroxide, caro's acid (H2SO5) is produced.

When the lead oxide is heated at 340oC in the presence of current air to produce

  1. Pb3O4

  2. Pb2O3

  3. PbO2

  4. Na2PO2

  5. None of these


Correct Option: A
Explanation:

This option is correct because when yellow lead monoxide is heated in a current of air to about 3400C for several hours, red lead is obtained.

Pure germanium is obtained by which of the following methods?

  1. Winkler's method

  2. Alexander's method

  3. Stock's method

  4. Merk's method

  5. None of these


Correct Option: A
Explanation:

This option is correct because germanium oxide gives red heat in a current of H2 at 540oC, to give pure germanium.

Biuret test is used for the detection of

  1. proteins

  2. fats

  3. vitamin C

  4. sugars

  5. None of these


Correct Option: A
Explanation:

This option is correct because the biuret test is a chemical test used for detecting the presence of peptide bond. In the presence of the peptide bonds, copper (II) ions form violet-coloured coordination complexes in an alkaline solution.

Which of the following reagents is/are used to detect sugar in the urine?

  1. Brady's reagent

  2. Fehling's reagent

  3. Baeyer's reagent

  4. Tollen's reagent

  5. Both (3) and (4)


Correct Option: B
Explanation:

This option is correct because the fehling's reagent can be used as a screen for the glucose in the urine. 

Which one of the following proteins helps to control the metabolism of glucose?

  1. Oxytocin

  2. Kreatin

  3. Insulin

  4. Haemoglobin

  5. None of these


Correct Option: C
Explanation:

This option is correct because the insulin is the peptide hormones produced by the beta cells in pancreas. It regulates the metabolism of carbohydrates and fats by promoting the adsorption of glucose.

Which of the following is/are the function(s) of PF3?

  1. Inhibits haemoglobin

  2. Tartar emetic

  3. Dyeing and pottery

  4. Fluorinating agent

  5. Both (3) and (4)


Correct Option: A
Explanation:

This option is correct because the trifluoro phosphine is act as the pi-accepter ligand. On the basis of this fact, it binds up with the metal of the haemoglobin to produce M-CO bonding which inhibits the action of haemoglobin in blood.

Which of the following is used for softening hard water?

  1. (NaPO3)6

  2. Ca(NO3)2.NH4NO3

  3. Ca(H2PO4)2.+CaSO4.2H2O

  4. KNO3

  5. None of these


Correct Option: A
Explanation:

This option is correct because sodium hexametaphosphate is a polymeric salt of metaphosphoric acid. It is used for softening hard water under the trade name calgon.

Calcium hydride is reduced in the presence of carbon dioxide to give

  1. calcium hyposulphite

  2. calcium oxilate

  3. calcium hydroxide

  4. calcium nitrite

  5. None of these


Correct Option: B
Explanation:

This option is correct because when calcium hydride or hydrolith are reduced in the presence of carbon dioxide, calcium oxilate is produced.

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