1214 + Interview Questions in Chemistry in Class 8 Page 12 InterviewSolution

551.	Name the phenomena causing the following events: (i) Formation of dew. (ii) Disappearance of naphthalene balls. (iii) Drying of wet clothes, (iv) Formation of snow. (v) Formation of cloud.
Answer» SOLUTION :(i) Condensation of water VAPOUR (II) SUBLIMATION of naphthalene BALLS (iii) Evaporation of water (iv) Deposition of water vapour (v) Condensation of water vapour

Discussion

552.	Name the most commonly found phosphates in nature.
Answer» SOLUTION : CALCIUM PHOSPHATE `(CA_3,(PO_3)_2)`

Discussion

553.	Name the metals which react with oxyegen at room temperature.
Answer» SOLUTION :SODIUM and POTASSIUM.

Discussion

554.	Name the metalloids and state the reasons why they are categorized as metalloids.
Answer» SOLUTION :(i) PROPERTIES ofmetalloids (II) ALLOTROPIC FORMS.

Discussion

555.	Name the layers of the atmosphere.
Answer» SOLUTION :TROPOSPHERE, STRATOSPHERE, MESOSPHERE and THERMOSPHERE.

Discussion

556.	Name the isotopes of hydrogen and give the number of neutrons present in each of them.
Answer» SOLUTION :`""_(1)H^(1), _(1)H^(2), _(1)H^(3)`

Discussion

557.	Name the different types of instruments used to measure atmospheric pressure.
Answer» SOLUTION :MERCURY BAROMETER, ANEROID barometer.

Discussion

558.	Name the chemicals which give fruits their smell.
Answer» ANSWER :The CHEMICALS which GIVE fruits their smell are ESTERS.

Discussion

559.	Name the acid formed by the reaction between SO_(2) gas and water . Also write the reaction involved.
Answer» SOLUTION :`SO_(2) + H_(2)O to H_(2)SO_(3)`

Discussion

560.	Name some of the pollutants produced by vehicles.
Answer» Answer :The pollutants PRODUCED by vehicles include carbon MONOXIDE, carbon dioxide, nitrogen OXIDES and smoke.

Discussion

561.	Name some of the major greenhouse gases.
Answer» Answer :The major GREENHOUSE gases are : Carbon DIOXIDE ,OZONE,Methane,Nitrous oxide,Chlorofluorpcarbons (CFCS),Water vapour

Discussion

562.	Name Some metals and non-metals.
Answer» Answer :Iron,COPPER,ALUMINIUM,zinc,GOLD and SILVER,etc. are some metals. Some NON metals are carbon,nitrogen,oxygen,sulphur,coal etc.

Discussion

563.	Name some measures to control air pollution.
Answer» SOLUTION :(i) PLANTS (ii) Environment friendly chemicals (III) Disposal of WASTE products.

Discussion

564.	Name the green houses gases.
Answer» ANSWER :Methane, nitrous OXIDE, WATER VAPOUR and carbon dioxide are some GREENHOUSE gases.

Discussion

565.	Name some compounds where the presence of water molecules provides colour ot those substance.
Answer» SOLUTION :`CuSO_(4).5H_(2)O, FeSO_(4).7H_(2)O`

Discussion

566.	Name differenceallotropes of carbon.
Answer» SOLUTION :CRYSTALLINE: DIAMOND, graphite and fullerene. AMORPHOUS: Charcoal l,coke , lampblack and gas carbon.

Discussion

567.	Name a reactive non-metal.
Answer» ANSWER :PHOSPHORUS is a REACTIVE non-metal

Discussion

568.	Name a pollutant which is also used in refrigerators.
Answer» ANSWER :A POLLUTANT also USED in refrigerators is chlorofluorocarbons (CFCs).

Discussion

569.	Name a metal which is in liquid state at room temperature.
Answer» ANSWER :Mercury is the only METAL which is in LIQUID state at room temperature.

Discussion

570.	name a few components of pertroleum
Answer» ANSWER :PETROLEUM gas, petrol, diesel,LUBRICATING OIL and paraffin wax are a few components of petroleum.

Discussion

571.	Na_(2)O + CO_(2) to …………..
Answer» ANSWER :`Na_(2)CO_(3)`

Discussion

572.	Na_(2)CO_(3).10H_(2)O on exposure to air loses some water of crystallization and the rest on heating . How do you account for the above phenomenon ?
Answer» Solution :`Na_(2)CO_(3).H_(2)O` on exposure to air loses nine water moleclues from its water of crystallization because initially vapour pressure of the compound is more than vapour pressure of the MOISTURE PRESENT in the ATMOSPHERIC air. It is an example of an efflorescent substance. After the release of nine molecules of water of crystallization its vapour pressure becomes equal to the pressure of the moisture present in atmosphere. Hence removal of 10TH water molecule requires.

Discussion

573.	N_(2 is ________ in KOH solution while CO_(2) is _________.
Answer» ANSWER :INSOLUBLE, SOLUBLE

Discussion

574.	N_2+3H_2to2NH_3+X kcal/X mole, then the formation of NH_3 involves ___________ of energy with respect to reactants.
Answer» SOLUTION :EVOLUTION

Discussion

575.	My mother always buys PET bottles and PET jars for storing rice and sugar. I wonder what PET is?
Answer» Answer :PET STANDS for Poly+Ester+Terylene. It is one of the most popular FORM of polyester (poly+ester) which finds its use in a variety of USEFUL PRODUCTS such as bottles, jars, utensils, films, wires, etc.

Discussion

576.	Most of the ______ can be recycled.
Answer» ANSWER :C

Discussion

577.	Most of the alpha-particles passed straight through the gold foil. This proved the existence of ______ inan atom.
Answer» SOLUTION :EMPTY SPACE

Discussion

578.	MnO_(2) used as a catalyst in the preparation of oxygen from KClO_(3) should be completely free of carbon. Justify.
Answer» Solution :`MnO_(2)` usually contains coal as impurity. If such `MnO_(2)` is used, carbon when heated with potassium chlorate leads to an EXPLOSION with the release of enormous amount of heat since it is a highly EXOTHERMIC reaction.

Discussion

579.	Mixture with uniform composition.
Answer» SOLUTION :HOMOGENEOUS MIXTURE

Discussion

580.	Miscible liquids form separate layers in a mixture.
Answer» ANSWER :F

Discussion

581.	Middle zone of the candle is __________in colour.
Answer»

Discussion

582.	Method to separate solid dissolved in water.
Answer» SOLUTION :EVAPORATION

Discussion

583.	Method to separate an insoluble solid from solid-liquid mixture.
Answer» SOLUTION :FILTRATION

Discussion

584.	..................method is used to separate wheat grains from its husk.
Answer» SOLUTION :WINNOWING

Discussion

585.	Methane is prepared in laboratory by heating anhydrous sodium acetate with ________
Answer» ANSWER :SODA LIME

Discussion

586.	Metals that react with steam to form metal oxides.
Answer» ANSWER :MAGNESIUM, ZINC, IRON and ALUMINIUM

Discussion

587.	Metals form basic oxides or amphoteric oxides.
Answer» ANSWER :1

Discussion

588.	Metallic oxides on reaction with water give ______.
Answer» ANSWER :HASES

Discussion

589.	Metal oxides react with water to produce metal hydroxides.
Answer» ANSWER :t

Discussion

590.	Mention two physical properties of methane.
Answer» SOLUTION :COLOURLESS, ODOURLESS insoluble in WATER and lighter than air.

Discussion

591.	Mention three reasons responsible for the scarcity of water.
Answer» ANSWER :THREE reasons responsible for the SCARCITY of water are : Increase inpopulation. Increase in industries and Increase in use ofchemical fertilisers, WEEDICIDES, insecticides, etc. in agricultural activities.

Discussion

592.	Mention the uses of chlorine
Answer» Solution :(i) BLEACHING action (ii) Nature (III) Extraction of METALS (iv) Industries

Discussion

593.	Mention the properties of metals:
Answer» Answer :The PROPERTIES of metals are : HARDNESS,lustrous, MALLEABLE, DUCTILE, sonorous, and good conductor of heat and electricity

Discussion

594.	Mention the chemical formulae of (i) Phosgene (ii) tear gas and (iii) chloroform
Answer» SOLUTION :`COCL_2` (II) `"CC"l_3NO_2` (III)`CHCL_3`

Discussion

595.	Mention the chemical properties of sodium carbonate.
Answer» Solution :`(i) Na_(2)CO_(3)+H_(2)O to H_(2)CO_(3)+2NAOH` (ii) REACTS with metal salts to form INSOLUBLE basic carbonates.

Discussion

596.	Mention the chemical properties of diamond.
Answer» SOLUTION :(i) Reaction with `O_(2)` (II) Reaction with SODIUM carbonate .

Discussion

597.	Mention some of the sources of air pollutants.
Answer» Answer :Some of the SOURCES of air POLLUTANTS are factories, power plants, automobile EXHAUSTS and burning of firewood and DUNG cakes.

Discussion

598.	Mention one aspect which makes synthetic fibres similar to natural fibres.
Answer» ANSWER :SYNTHETIC fibres are similar to natural fibres in one aspect, i.e. syntetic fibres can also be WOVEN into fabrics like fibres.

Discussion

599.	Mention any two physical propertiesof carbon dioxide.
Answer» SOLUTION :Highly soluble in water , heavier than AIR.

Discussion

600.	Melting point of diamond is _______.
Answer» SOLUTION :`3700^(@)C`

Discussion

Explore topic-wise InterviewSolutions in .

Name the phenomena causing the following events: (i) Formation of dew. (ii) Disappearance of naphthalene balls. (iii) Drying of wet clothes, (iv) Formation of snow. (v) Formation of cloud.

Name the most commonly found phosphates in nature.

Name the metals which react with oxyegen at room temperature.

Name the metalloids and state the reasons why they are categorized as metalloids.

Name the layers of the atmosphere.

Name the isotopes of hydrogen and give the number of neutrons present in each of them.

Name the different types of instruments used to measure atmospheric pressure.

Name the chemicals which give fruits their smell.

Name the acid formed by the reaction between SO_(2) gas and water . Also write the reaction involved.

Name some of the pollutants produced by vehicles.

Name some of the major greenhouse gases.

Name Some metals and non-metals.

Name some measures to control air pollution.

Name the green houses gases.

Name some compounds where the presence of water molecules provides colour ot those substance.

Name differenceallotropes of carbon.

Name a reactive non-metal.

Name a pollutant which is also used in refrigerators.

Name a metal which is in liquid state at room temperature.

name a few components of pertroleum

Na_(2)O + CO_(2) to …………..

Na_(2)CO_(3).10H_(2)O on exposure to air loses some water of crystallization and the rest on heating . How do you account for the above phenomenon ?

N_(2 is ________ in KOH solution while CO_(2) is _________.

N_2+3H_2to2NH_3+X kcal/X mole, then the formation of NH_3 involves ___________ of energy with respect to reactants.

My mother always buys PET bottles and PET jars for storing rice and sugar. I wonder what PET is?

Most of the ______ can be recycled.

Most of the alpha-particles passed straight through the gold foil. This proved the existence of ______ inan atom.

MnO_(2) used as a catalyst in the preparation of oxygen from KClO_(3) should be completely free of carbon. Justify.

Mixture with uniform composition.

Miscible liquids form separate layers in a mixture.

Middle zone of the candle is __________in colour.

Method to separate solid dissolved in water.

Method to separate an insoluble solid from solid-liquid mixture.

..................method is used to separate wheat grains from its husk.

Methane is prepared in laboratory by heating anhydrous sodium acetate with ________

Metals that react with steam to form metal oxides.

Metals form basic oxides or amphoteric oxides.

Metallic oxides on reaction with water give ______.

Metal oxides react with water to produce metal hydroxides.

Mention two physical properties of methane.

Mention three reasons responsible for the scarcity of water.

Mention the uses of chlorine

Mention the properties of metals:

Mention the chemical formulae of (i) Phosgene (ii) tear gas and (iii) chloroform

Mention the chemical properties of sodium carbonate.

Mention the chemical properties of diamond.

Mention some of the sources of air pollutants.

Mention one aspect which makes synthetic fibres similar to natural fibres.

Mention any two physical propertiesof carbon dioxide.

Melting point of diamond is _______.