Dr Viraf J Dalal Chemistry Class 8. We covered all the Dr Viraf J Dalal Chemistry Class 8 MCQs in this post for free so that you can practice well for the exam.
Install our MCQTUBE Android app from the Google Play Store and prepare for any competitive government exams for free.
These types of competitive MCQs appear in exams like SSC, Railway, Bank, Delhi Police, UPSSSC, UPSC (Pre), State PCS, CDS, NDA, Assistant Commandant, and other Competitive Examinations, etc.
We created all the competitive exam MCQs into several small posts on our website for your convenience.
You will get their respective links in the related posts section provided below.
Related Posts:
Dr Viraf J Dalal Chemistry Class 8 Objective for Students
Alkanals without an α-hydrogen atom, on heating with conc. NaOH undergoes oxidation and reduction to form a mixture of carboxylic acid and alcohol. This reaction is called:
(A) Wolff-Kishner reaction
(B) Clemmensen’s reaction
(C) Haloform reaction
(D) Cannizzaro’s reaction
Option d – Cannizzaro’s reaction
Formaldehyde, on heating with 50% caustic soda, forms ( Dr Viraf J Dalal Chemistry Class 8 MCQ )
(A) A mixture of methanol and sodium formate
(B) A mixture of ethanol and potassium formate
(C) A mixture of propanol and sodium acetate
(D) A mixture of methanal and sodium methanoate
Option a – A mixture of methanol and sodium formate
Neovaleraldehyde and benzene carbaldehyde, on heating with 50% NaOH, form how many different disproportionation products?
(A) Three
(B) Four
(C) Five
(D) Six
Option b – Four
The major product formed during the crossed Cannizzaro’s reaction between formaldehyde and benzaldehyde is ( Dr Viraf J Dalal Chemistry Class 8 MCQ )
(A) Methyl alcohol and alkali formate
(B) Benzyl alcohol and alkali benzoate
(C) Benzyl alcohol and alkali formate
(D) Methyl alcohol and alkali formate
Option c – Benzyl alcohol and alkali formate
During the cross aldol condensation between methanal and ethanal, the major product is:
(A) Simple condensation of methanal
(B) Simple condensation product of ethanal
(C) Crossed condensation product
(D) Condensation cannot take place
Option c – Crossed condensation product
CNG used in automobiles to check pollution mainly consists of ( Dr Viraf J Dalal Chemistry Class 8 MCQ )
(a) CH4
(b) CO2
(c) N₂
(d) H₂
Option a – CH4
Pyrethrin used in mosquito coil is obtained from
(a) a seed plant
(b) an insect
(c) a bacterium
(d) a fungus
Option a – a seed plant
Biogas mainly consists of ( Dr Viraf J Dalal Chemistry Class 8 MCQ )
(a) carbon dioxide and hydrogen
(b) hydrogen and methane
(c) carbon dioxide and methane
(d) hydrogen and oxygen
Option c – carbon dioxide and methane
C11-L-methyl-methionine is used for a
(a) brain tumor and parathyroid imaging
(b) stomach analysis
(c) bone imaging
(d) live imaging
Option a – brain tumor and parathyroid imaging
Petroleum gas is a mixture of ethane, propane, and butane. What are its major constituents? ( Dr Viraf J Dalal Chemistry Class 8 MCQ )
(a) Ethane
(b) Propane
(c) Butane
(d) All three are present in equal proportions
Option c – Butane
The new strain of bacteria produced by biotechnology in the alcohol industry is
(a) Escherichia coli
(b) Saccharomyces cerevisiae
(c) Bacillus subtilis
(d) Pseudomonas putida
Option d – Pseudomonas putida
Soap helps in cleaning clothes because ( Dr Viraf J Dalal Chemistry Class 8 MCQ )
(a) the chemical of soap changes
(b) it increases the surface tension of the solution
(c) it absorbs the dirt
(d) it lowers the surface tension of the solution
Option d – it lowers the surface tension of the solution
Which of the following options is false about a soap?
(a) The soap solution in water is neutral and can be used to wash all kinds of fabrics
(b) Soap forms lather only in soft water
(c) Soap is a metallic salt of higher fatty acids
(d) Soap cannot be used in slightly acidic medium
Which of the following hydrocarbons undergo additional reactions? C₂H6, C3H8, C3H6, C₂H₂, and CH4 ( Dr Viraf J Dalal Chemistry Class 8 MCQ )
(a) C₂H6 and C3H8
(b) C3H6 and C₂H₂
(c) CH4 and C₂H6
(d) C₂H8 and C₂H₂
Option b – C3H6 and C₂H₂
The order of appearance of the following with increasing temperature during the refining of crude oil is
(a) Kerosene, gasoline, diesel
(b) Diesel, gasoline, kerosene
(c) Gasoline, kerosene, diesel
(d) Gasoline, diesel, kerosene
Option c – Gasoline, kerosene, diesel
What is a “Kiss of death”? ( Dr Viraf J Dalal Chemistry Class 8 MCQ )
(a) A flower whose smell was the basis of a discovery on the smell that led to the award of the 2004 Nobel Prize in Medicine.
(b) A protein degradation mechanism whose discovery ultimately won the scientists the 2004 Nobel Prize in Chemistry.
(c) A good wine flavor working on which scientists won the 2004 Nobel Prize in Chemistry.
(d) A network in the brain associated with smell whose discovery led the scientists to win the 2004 Nobel Prize in Physiology and Medicine.
Option b – A protein degradation mechanism whose discovery ultimately won the scientists the 2004 Nobel Prize in Chemistry
Why are large alkane molecules cracked to form smaller molecules to use as fuel?
(a) It forms only 20% of the crude oil.
(b) To meet the demand for small alkane molecules.
(c) Crude oil does not contain small alkane molecules.
(d) Small alkane molecules can be polymerized.
Option b – To meet the demand for small alkane molecules
Which physical property of the alkanes does not increase as relative molecular mass increases? ( Dr Viraf J Dalal Chemistry Class 8 MCQ )
(a) Boiling point
(b) Flammability
(c) Melting point
(d) Viscosity
Option b – Flammability
One mole of hydrocarbon ‘X’ reacted completely with one mole of hydrogen gas in the presence of a heated catalyst. What could be the formula of ‘X’?
(a) C₂H6
(b) C4H10
(c) C5H10
(d) C7H16
Option c – C5H10
A hydrocarbon has a molecular formula of C6H12. It does not react with hydrogen to give C6H14 nor does it react with chlorine to give C6H12C12. The hydrocarbon C6H12 is. A. A saturated hydrocarbon B. An unsaturated hydrocarbon C. An open chain hydrocarbon D. A cyclo-alkane ( Dr Viraf J Dalal Chemistry Class 8 MCQ )
(a) A and B
(b) C and D
(c) D and B
(d) A and D
Option d – A and D
An organic compound is a clear liquid having a molecular C4H8O. It has an open chain structure. Without a formula any carbon-carbon double bond. The compound can be (A) alcohol (B) an ester (C) an aldehyde (D) a ketone
(a) (A) and (B)
(b) (C) and (D)
(c) (B) and (D)
(d) (D) and (A)
Option b – (C) and (D)
When ethane is burnt in excess of air, the products of combustion are ( Dr Viraf J Dalal Chemistry Class 8 MCQ )
(a) C and H₂O
(b) CO and H₂O
(c) CO₂ and H₂
(d) CO₂ and H₂O
Option d – CO₂ and H₂O
The number of oxygen molecules used in the combustion of 1 molecule of ethanol is
(a) 1
(b) 2
(c) 3
(d) 4
Option c – 3
Which of the following is incorrectly matched ( Dr Viraf J Dalal Chemistry Class 8 MCQ )
(a) vinegar → carboxylic acid
(b) C₂H6 → alkane
(c) ethanol →alcohol
(d) methanol →ketone
Option d – methanol →ketone
What is the IUPAC Name of t-butyl alcohol?
(a) Butanol-2
(b) 2-Methyl propan-2-ol
(c) Butanol-1
(d) Propanol 2
Option b – 2-Methyl propan-2-ol
Oil and water can form a stable dispersion with the help of a third substance commonly called ( Dr Viraf J Dalal Chemistry Class 8 MCQ )
(a) emulsifier
(b) dispersant
(c) protective colloid
(d) None of these
Option a – emulsifier
An atom is
(a) The smallest particle of matter known
(b) The smallest particle of a gas
(c) The smallest indivisible particle of an element that can take part in a chemical change
(d) Radioactive emission
Option c – The smallest indivisible particle of an element that can take part in a chemical change
Which of the following is a compound? ( Dr Viraf J Dalal Chemistry Class 8 MCQ )
(a) Stainless steel
(b) Brass
(c) Iron sulphide
(d) Diamond
Option c – Iron sulphide
Select the one that has a definite boiling point
(a) true solution
(b) compound
(c) colloid
(d) All of these
Option b – compound
We can see the particles of a colloidal solution with
(a) naked eyes
(b) the help of an ultramicroscope
(c) the help of a microscope
(d) None of these
Option c – the help of a microscope
Which of the following will yield a mixture?
(a) Crushing of marble tile
(b) Breaking of ice-cubes
(c) Addition of sodium metal to water in a china dish
(d) Agitating a detergent with water in a washing machine.
Option d – Agitating a detergent with water in a washing machine
On passing through a colloidal solution, the beam of light gets ……
(a) reflected
(b) refracted
(c) scattered
(d) absorbed
Option c – scattered
The cause of the Brownian movement is
(a) convection current
(b) heat changes in a liquid state
(c) impact of molecules of dispersion medium on colloidal particles.
(d) attractive forces between particles of the dispersed phase and the dispersion medium.
Option c – impact of molecules of dispersion medium on colloidal particles
Brass is an example of
(a) compound
(b) element
(c) homogeneous mixture
(d) heterogeneous mixture
Option c – homogeneous mixture
Air is regarded as a mixture because
(a) its pressure may vary
(b) its temperature may vary
(c) its volume changes with temperature/ change in pressure
(d) its composition may vary
Option d – its composition may vary
Which of the following statements is true for pure substances? (i) Pure substances contain only one kind of particle (ii) Pure substances may be compounds or mixtures (iii) Pure substances have the same composition throughout (iv) Pure substances can be exemplified by all elements other than nickel
(a) (i) and (ii)
(b) (i) and (iii)
(c) (iii) and (iv)
(d) (ii) and (iii)
Option b – (i) and (iii)
When a gas is compressed while keeping the temperature constant, it results in
(a) an increase in the speed of gaseous molecules
(b) an increase in a collision among gaseous molecules
(c) a decrease in the speed of gaseous molecules
(d) a decrease in collision among gaseous molecules
Option b – an increase in a collision among gaseous molecules
Which of the following is an element?
(a) Marble
(b) Graphite
(c) Washing stone
(d) Stone
Option b – Graphite
The one, in which interparticle forces are strongest, is
(a) sodium chloride
(b) hydrogen
(c) ether
(d) carbon dioxide
Option a – sodium chloride
The melting point temperature of the solid state of a substance is 40°C. The freezing point temperature of the liquid state of the same substance will be
(a) 35°C
(b) 40°C
(c) 45°C
(d) can’t predict
Option b – 40°C
Which one will help to accelerate the process of evaporation of a liquid kept in an open china dish?
(a) Keeping the dish open
(b) Blowing air into the liquid
(c) Keeping the dish under a running fan
(d) All of the above
Option d – All of the above
The blue color of water in the sea is due to
(a) absorption of another color except for blue by water molecules
(b) scattering of blue light by sol particles
(c) refraction of blue light by impurities present in seawater
(d) reflection of blue sky by seawater
Option b – scattering of blue light by sol particles
Tails of comets are visible due to
(a) Tyndall Effect
(b) Reflection
(c) Brownian movement
(d) None of these
Option a – Tyndall Effect
Why is helium preferred over hydrogen for use in airships?
(a) Helium has a low density
(b) Helium has a high density
(c) Helium is chemically less reactive
(d) Helium is chemically more reactive
Option c – Helium is chemically less reactive
Which one of the following mixtures is homogeneous?
(a) Starch and sugar
(b) Methanol and water
(c) Graphite and charcoal
(d) Calcium carbonate and calcium bicarbonate
Option b – Methanol and water
During summer, water kept in an earthen pot becomes cool because of the phenomenon of
(a) diffusion
(b) transpiration
(c) osmosis
(d) evaporation
Option d – evaporation
A few substances are arranged in the increasing order of ‘forces of attraction’ between their particles. Which one of the following represents a correct arrangement?
(a) Water, air, wind
(b) Air, sugar, oil
(c) Oxygen, water, sugar
(d) Salt, juice, air
Option c – Oxygen, water, sugar
The boiling points of diethyl ether, acetone, and n-butyl alcohol are 35°C, 56°C, and 118°C respectively. Which one of the following correctly represents their boiling points in the kelvin scale?
(a) 306 K, 329 K, 391 K
(b) 308 K, 329 K, 392 K
(c) 308 K, 329 K, 391 K
(d) 329 K, 392 K, 308 K
Option c – 308 K, 329 K, 391 K
In which of the following conditions, the distance between the molecules of hydrogen gas would increase? (i) Increasing pressure on hydrogen contained in a closed container (ii) Some hydrogen gas leaking out of the container (iii) Increasing the volume of the container of hydrogen gas (iv) Adding more hydrogen gas to the container without increasing the volume of the container
(a) (i) and (iii)
(b) (i) and (iv)
(c) (ii) and (iii)
(d) (ii) and (iv)
Option c – (ii) and (iii)
Tulsi plant has medicinal values due to the presence of the following:
(c) Phenols and Flavonoids
(d) None of the above
Option c – Phenols and Flavonoids
Which of the following is an example of a herbicide?
(a) Sodium chlorate
(b) Potassium permanganate
(c) Bleaching powder
(d) None of the above
Option a – Sodium chlorate
Who is regarded as the Father of Modern Chemistry?
(a) Rutherford
(b) Einstein
(c) Lavoisier
(d) C. V. Raman
Option c – Lavoisier
Which one of the following substances is NOT synthetic?
(a) Fibroin
(b) Lexan
(c) Neoprene
(d) Teflon
Option a – Fibroin
Which one of the following materials contains calcium?
(a) China clay
(b) Corundum
(c) Gypsum
(d) Talc
Option c – Gypsum
We covered all the dr viraf j dalal chemistry class 8 mcqs above in this post for free so that you can practice well for the exam.
Check out the latest MCQ content by visiting our mcqtube website homepage.
Also, check out:
