chemistry MCQs – Page 39

Practise multiple-choice questions from chemistry for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

chemistry Mcqs
761. Which of the elements show passivity when treated with conc. HNO3?
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A. Cr

B. A

C. All of the above

D. Fe

762. Phosphene gas will be produced if phosphorous acid is subjected to___________________?
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A. Oxidation

B. Reduction

C. Decomposition

D. Both b & c
763. The property which increases upto group IV-A then decreases on wards_______________?
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A. Atomic volume

B. Ionization energy

C. Melting & boiling points

D. Atomic radii

764. By which method the molecular mass of benzene was determined as 78.108 ?
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A. Vapour density method

B. X-ray diffraction method

C. Distillation methos

D. Specific gravity method

765. In diaphragm cell hydrogen is discharged by the reduction of__________________?
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A. Water

B. HCI

C. NaCl

D. Na+

766. In benzene sulphonic acid the sulphonic group is attached with benzene ring through ___________________?
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A. OH

B. Hydrogen

C. Oxygen

D. Sulphur
767. Which of the following substances does not give iodoform test ?
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A. acetaldehyde

B. ethyl alcohol

C. methyl alcohol

D. acetone

768. Which one of the following statement is not correct about benzene ?
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A. On hydrogenation 208 KJ/mole is liberated

B. Resonance energy of benzene is 150.5 K Cal/mole

C. Molecular mass of benzene is 78.108

D. C-H bond length in benzene is 1.09 A?

769. Which of the following is a symmetrical ketone___________________?
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A. butanone

B. acetone

C. 2-pentanone

D. 3 hexanone

770. Noble gases are named so because they are__________________?
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A. less reactive

B. All

C. Zero group elements

D. Having completely filled valence shell

771. Which of the following compounds will react with Tollens reagent ?
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A. CH3-COOH

B. CH3-CH-CH3

C. CH3-CHO

D. CH3-CO-CH2-CH3

772. Boron is non-netal whereas A1 is metal. It is due to_______________________?
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A. Small size

B. High nuclear charge

C. Both A and B

D. No authorized justification yet

773. Which of the p-block elements are not representative elements ?
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A. Halogens (VII-A)

B. Group-18 elements (VIII-A)

C. Group-14 elements (IV-A)

D. Alkali metals (I-A)

774. An acid with unpleasant smell_________________?
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A. formic acid

B. propionic acid

C. butyric acid

D. acetic acid

775. Because of its ability to combine with both oxygen and nitrogen aluminium metal is used_____________?
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A. To remove air bubbles from molten metal

B. As insulator

C. As nitrometer

D. To produce alloy

776. Elements with similar chemical properties appear in the_________________?
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A. Same family

B. p block elements

C. Right upper corner

D. Same period

777. The acid which is used as ink remover is_________________?
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A. Adipic acid

B. Acetic acid

C. Succinic acid

D. Oxalic acid
778. Carboxylic acid reacts with ammonia to form ammonium salts which on heating produces_______________?
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A. Ester

B. CO2

C. Acidamide

D. Alkane

779. Crystals of Na2CO3. 10H2O when exposed to air_________________?
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A. Remains unchanged

B. Lose water and remain solid

C. Gain water and become liquid

D. Gain water and remain solid

780. Which element can form tripositive ion ?
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A. Beryllium

B. Aluminium

C. Carbon

D. Silicon