On this Page we have given West Bengal Class 8 English Medium Science Solution Chapter 3 Know About Some Common Gases Question and Answer for our Students of West bengal Class 8 English Medium. Hope this following Question Answer will help our Students.
West Bengal Class 8 | Science | Know About Some Common Gases
Q.1.) MCQ
1) A common thermometer is used to measure the _____ of an object
a ) temperature b) static temperature c) dynamic temperature d) mass
Ans. Temperature
2) State which of the following statements is wrong regarding thermometer
a ) the calibration on a thermometer is called scale
b) there are the scales
c) the scales are Celsius , Fahrenheit , Kelvin
d ) the range of scales is always same
Ans. The range of scales is always same
3) When two or more dry cells are joined , they together are known as
a ) conjoined cells b) battery c) circuit d) electrolytic cell
Ans. Battery
4) The part of circuit which can stop and start the current flow is known as
a ) transistor b) terminal c) switch d) resistor
Ans. Switch
5) The electrical wires in our connections are generally made up of
a ) copper b) zinc c) iron d) lead
Ans. Copper
6) What are the advantages of an LED over a standard bulb
a ) they last longer
b) they do not get fused easily
c) it emits more light
d) both a and b
Ans. Both a and b
7) The Equipment that is used to measure the correct mass of a sample is
a ) chemical balance b) physical balance c) digital balance d) all of them can be used
Ans. Chemical balance
8) In a chemical balance a pair of forceps are used instead of hands because
a ) in can leave microorganisms on the sample
b ) it can lead to incorrect mass measurement
c ) it can damage the balance
d) all of them
Ans. It can lead to incorrect mass measurement
9) ______ is used to hold apparatus or something during the execution of an experiment
a ) table b) tripod stand c) test tube rack d) clamp and stand
Ans. Clamp and stand
10) Out of all the glass containers the most frequent used container is
a ) test tube b) conical flask c) round bottom flask d) beaker
Ans. Test tube
11) A ______ is a cylindrical glass container with a spout at it’s mouth
a ) conical flask b) woulfle bottle c) round bottom flask d) beaker
Ans. Beaker
12) A watch glass is used for
a ) to transfer a substance
b ) to take a substance in small quantity
c) to mix substances
d ) both a and b
Ans. To take a substance in small quantity
13) Identify the correct apparatus as shown in the figure
a ) clamp and stand
b) Tripod stand and wire gauze
c ) pipette and burette
d ) table
Ans. Tripod stand and wire gauze
14) Choose the correct function of a filter paper during an experiment
a ) it’s used to test the acidity
b ) it’s used to separate liquid
c ) it’s used to separate insoluble solids
d ) it’s used to powder crystals
Ans. It’s used to separate liquid
15) They were the first bacteria that split water to produce oxygen
a ) Staphylococcus b) Salmonella c) Bacillus d) Cyanobacteria
Ans. Cyanobacteria
16) The microorganisms that can survive without oxygen are known as
a ) aerobic b) obligate anaerobes c) heterotrophs d) autotrophs
Ans. Obligate anaerobes
17) The production of energy is _____ times stronger than in the absence of oxygen
a ) 12 b ) 13 c) 14 d) 15
Ans. 15
18) An enzyme present in our body can breakdown hydrogen peroxide into water and oxygen
a ) amylase b ) catalase c) lipase d) maltase
Ans. Catalase
19) The people who are suffering from pneumonia are usually given a mixture of
a ) oxygen and nitrogen b) oxygen and hydrogen
c ) oxygen and carbon dioxide d) oxygen and helium
Ans. Oxygen and carbon dioxide
20 ) The atmosphereis made up of a mixture of gases , out of which oxygen constitutes about ____ percent
a ) 20.6 b) 25 c) 22 d) 24
Ans. 20.6
21) What happens to oxygen molecule at high temperature?
a.) It becomes diatomic
b.) It dissociates to produce atomic oxygen
c.) It becomes a powerful reducing agent
d.) It becomes inert
Answer: B. It dissociates to produce atomic oxygen
22) What elements does oxygen not react with?
a.) Noble metals, halogens, and oxygen
b.) Noble gases, halogens, and oxygen
c.) Noble metals, halogens, and nitrogen
d.) Noble gases, halogens, and nitrogen
Answer: A. Noble metals, halogens, and oxygen
23) What type of change occurs during combustion of a substance?
a.) Reduction
b.) Oxidation
c.) Hydrolysis
d.) Polymerization
Ans: B. Oxidation
24) Why is controlled amounts of oxygen given to a patient suffering from respiratory problems?
a.) To reduce the oxygen levels in their body
b.) To reduce the carbon dioxide levels in their body
c.) To increase the oxygen levels in their body
d.) To increase the carbon dioxide levels in their body
Answer: C. To increase the oxygen levels in their body
25) What are the different types of oxides that can be produced when oxygen combines with elements?
a.) Acidic oxide, basic oxide, amphoteric oxide, and peroxides
b.) Basic oxide, amphoteric oxide, peroxides, and neutral oxide
c.) Acidic oxide, basic oxide, amphoteric oxide, and neutral oxide
d.) Acidic oxide, basic oxide, peroxides, and neutral oxide
Answer: A. Acidic oxide, basic oxide, amphoteric oxide, and peroxides
26.) What is the purpose of adding manganese dioxide to hydrogen peroxide solution in the experiment?
A) To prevent the reaction from occurring
B) To increase the rate of the reaction
C) To decrease the rate of the reaction
D) To change the color of the solution
Answer: B) To increase the rate of the reaction
27.) What caution should be taken while working with hydrogen peroxide solution?
A) It should be heated directly
B) It should be exposed to sunlight
C) It should be kept in an open container
D) It should be avoided to contact with skin or eyes
Answer: D) It should be avoided to contact with skin or eyes
28) What is the equation for the reaction that occurs in the experiment for the preparation of oxygen from sodium peroxide?
A) Na2O + 2H2O → 2NaOH + H2
B) Na2O2 + 2H2O → 2NaOH + O2
C) Na2O2 + 2H2O → 2NaH + O2
D) Na2O + 2HCl → 2NaCl + H2O
Answer: B) Na2O2 + 2H2O → 2NaOH + O2
29) What gas is collected in the gas jar in the preparation of oxygen from sodium peroxide experiment?
A) Carbon dioxide
B) Hydrogen gas
C) Nitrogen gas
D) Oxygen gas
Answer: D) Oxygen gas
30) Which of the following is true about the combustibility of hydrogen gas?
A) Hydrogen gas does not help in burning.
B) Hydrogen gas ignites with an explosion when mixed with oxygen.
C) Hydrogen gas is not inflammable.
D) Hydrogen gas burns with a yellow flame.
Answer: Hydrogen gas ignites with an explosion when mixed with oxygen.
31) What happens when hydrogen gas reacts with chlorine gas in the presence of diffused sunlight?
A) No reaction occurs.
B) Hydrogen chloride gas is produced.
C) An explosion takes place.
D) Hydrogen and chlorine gas dissociate into atoms.
Answer: Hydrogen chloride gas is produced
32) What is atomic hydrogen?
A) A diatomic molecule of hydrogen.
B) A powerful reducing agent produced when hydrogen gas is passed through an electric discharge.
C) A mixture of hydrogen and oxygen that burns with a blue flame.
D) A pungent smelling gas produced when hydrogen and nitrogen combine in the presence of an iron catalyst.
Answer: A powerful reducing agent produced when hydrogen gas is passed through an electric discharge.
33) Which of the following statements about the isotopes of hydrogen is true?
A) There are four isotopes of hydrogen.
B) The natural abundance of all three isotopes of hydrogen is large.
C) The chemical properties of the three isotopes of hydrogen are identical.
D) The chemical properties of the three isotopes of hydrogen are different.
Answer: The chemical properties of the three isotopes of hydrogen are different.
34) According to the passage, what happens when hydrogen gas is passed over yellow-colored molten sulfur?
a) Hydrogen sulfide gas is produced with the smell of rotten eggs
b) Metallic hydrides are formed
c) Copper is produced by reducing hot, black cupric oxide
d) Hydrogen gas is bound to the surface of certain metals
Answer: Hydrogen sulfide gas is produced with the smell of rotten eggs
35.) Which of the following statements about hydrogen is true?
- a) Hydrogen is almost insoluble in water
- b) Hydrogen helps in burning
- c) Hydrogen does not react with non-metals
- d) Hydrogen is a powerful oxidizing agent
Answer: a) Hydrogen is almost insoluble in water
36.) What is the process called in which some metals can bind hydrogen gas on their surface at normal temperature?
A) Reduction
b) Adsorption
c) Combustion
d) Dissociation
Answer: Adsorption
37.) What is the product of the reaction between copper oxide and hydrogen gas?
A) CuO
b) Cu
c) HO
d) H2SO4
Answer: Cu
38.) Which of the following equations represents the reaction between aluminum and hydrochloric acid?
A) Zn + H2SO4 (dilute) → ZnSO4 + H2
b) Mg + HCl (dilute) → MgCl2 + H2
c) Fe + H2SO4 (dilute) → FeSO4 + H2
d) Al + HCl (dilute) → AlCl3 + H2
Answer: Al + HCl (dilute) → AlCl3 + H2
Q.(2) Short answer questions.
(1) Name two equipment’s used in laboratory?
→
- Bunsen burner
- Spirit lamp
- Thermometer
(2) How much oxygen gas present in surroundings by volume?
→ 20.6% oxygen is present in surroundings by volume.
(3) How ozone is formed ?
→ Ozone is formed in the upper atmosphere due to solar ultraviolet radiation on gaseous oxygen.
(4) What is the use of ozone layer?
→It protects the earth’s surface by damaging from ultraviolet radiation of the sun.
(5) What is the freezing point of liquid oxygen?
→-218 degree Celsius
(6) Give one physical property of oxygen ?
→
- It is colorless, odorless, tasteless gas at ordinary temperature.
(7) Give one chemical property of oxygen ?
→Oxygen is diatomic but at High temple it dissociates into atomic oxygen and acts as strong oxidizing agent.
(8) What is the Nature of white powder of magnesium oxide?
→ It is basic in nature.
(9) Explain the formation of peroxide with oxygen ?
→Oxygen reacts with hot sodium to form sodium peroxide which further reacts with water produce hydrogen peroxide.
(10) What is the main use of hydrogen ?
→ Main use of hydrogen gas is to produce Ammonia.
(11) How hydrogen manufactured in chemical industry?
→ Hydrogen manufactured in the chemical industry from the natural gas .
(12) Is hydrogen gas has colour ?
→No , it is colorless gas .
(13) Explain about the solubility of hydrogen in water ?
→ Hydrogen is almost insoluble in water.
(14) Are hydrogen helps burning?
→ No , hydrogen gas is flammable but doesn’t helps burning.
(15) What is the product when hydrogen reacts with non-metals ?
→When hydrogen reacts with non-metals, it produces their hydrides.
(16) Which metals helps in adsorption of hydrogen on their surface ?
→
- Palladium
- Platinum
- Iron
- Cobalt
- Nickel
(17) How adsorption occurs with hydrogen ?
→ The above metals bind hydrogen gas normal temperature called as adsorption.
(18) What is occlusion ?
→ Subsequent heating of the metals released the hydrogen adsorbed on it called as occlusion.
(19) What happens when calcium reacts with cold water ?
→ When calcium reacts with cold water calcium hydroxide and hydrogen gas is produced.
(20) Write the chemicals required for the preparation of hydrogen gas in a laboratory?
→
- Impure zinc granules
- Distilled water
- Dilute sulphuric acid
(21) What happens when zinc is react with dilute sulphuric acid ?
→When zinc is reacted with dilute sulphuric acid zinc sulphate in hydrogen gas is produced.
Zn + H2SO4→ ZnSO4 + H2
(22) Give the reaction of reduction of cupric oxide ?
→ CuO + H2→ Cu + H2O
(23) What happens when hydrogen gas is passes over yellow coloured molten Sulphur ?
→ Hydrogen sulfide gas is produced with the smell of Rotten eggs.
(24) What happens when hydrogen reacts with hot Calcium?
→ Calcium hydrides are formed.
(25) What happens when potassium pyrogallate solution absorbs oxygen ?
→ It will turn brown.
(26) What happens when ammoniacal cuprous chloride absorbs oxygen ?
→It will turn blue .
(27) Give the reaction of oxidation of colorless nitric oxide?
→2NO + O2→ 2NO2
(28) What is amphoteric oxides ?
→They undergo neutralization reaction with both acids and bases.
(29) Explain the combustion of oxygen ?
→During combustion, combustible substances or one or more it’s constituents gets oxidized by combining with oxygen.
(30) State the boiling point of oxygen ?
→Boiling point of oxygen is -183 degree Celsius.
Also See: Previous Chapter Occurrence of Carbon and its Compounds in Nature Question Answer
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