Chemistry

Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.

Matter (Kinetic Molecular Theory)

Subtopic

Matter (Kinetic Molecular Theory) under Chemistry for Grade 8 ICSE.

Preview questions (no answers)

1.
$What happens to the kinetic energy of molecules as we heat a liquid?$
A. $It decreases$
B. $It increases$
C. $It remains the same$
D. $It first increases then decreases$
2.
$Intermolecular space is almost negligible in:$
A. $Alcohol$
B. $Oxygen$
C. $Iron$
D. $Milk$
3.
$What is the name for the process of converting a gas into a liquid?$
A. $Liquefaction$
B. $Solidification$
C. $Vaporization$
D. $Fusion$
4.
$Gases exert pressure on the walls of the container because:$
A. $Gases have weight$
B. $Gas molecules collide with the walls$
C. $Gases are very light$
D. $Gases have high density$
5.
$According to the Kinetic Molecular Theory, the physical state of a substance is determined by the balance between the intermolecular force of attraction and the kinetic energy of its particles. Based on the flowchart, which label represents the state where particles have enough kinetic energy to move past one another while remaining attracted to each other?$
A. $Label A$
B. $Label B$
C. $Label C$
D. $None of these$
6.
$Which of the following describes the behavior of molecules in a solid?$
A. $They flow easily from one place to another$
B. $They have high translatory kinetic energy$
C. $They are held together by very strong cohesive forces$
D. $They have the largest intermolecular spaces$
7.
$Which property allows a small amount of perfume to be detected from a distance?$
A. $High density of gases$
B. $Rapid diffusion of gas molecules$
C. $Strong cohesive forces in gases$
D. $Low kinetic energy of gas molecules$
8.
$If two different gases at the same temperature have different pressures, which of the following MUST be different according to KMT (assume equal volume)?$
A. $Average kinetic energy per molecule.$
B. $The total number of molecules.$
C. $The mass of individual molecules.$
D. $The color of the gases.$
9.
$When a gas is cooled at constant volume, the pressure decreases. Which KMT explanation is correct?$
A. $The molecules become smaller.$
B. $The number of molecules decreases.$
C. $The molecules move slower and hit the walls with less force and less often.$
D. $The intermolecular spaces decrease.$
10.
$What is the result of the 'unbalanced' cohesive forces acting on molecules at the surface of a liquid?$
A. $Evaporation$
B. $Boiling$
C. $Surface Tension$
D. $Viscosity$

Download the worksheet for Chemistry - Matter (Kinetic Molecular Theory) to practice offline. It includes additional chapter-level practice questions.

Physical and Chemical Changes

Subtopic

Physical and Chemical Changes under Chemistry for Grade 8 ICSE.

About Topic & Revision

Preview questions (no answers)

1.
$The fermentation of sugar into alcohol by yeast is a:$
A. $Physical change$
B. $Chemical change$
C. $Reversible process$
D. $None of these$
2.
$Crushing an aluminum can is a physical change because:$
A. $The metal becomes a different element$
B. $The mass of the can increases$
C. $Only the shape of the can changes$
D. $A gas is released during crushing$
3.
$Which of the following is NOT a chemical change?$
A. $Ripening of fruit$
B. $Melting of ice cream$
C. $Digestion of food$
D. $Burning of coal$
4.
$Drying of wet clothes in the sun is a:$
A. $Chemical change$
B. $Physical change$
C. $Biological change$
D. $Nuclear change$
5.
$In which of the following cases does a chemical change take place?$
A. $Drying of wet clothes$
B. $Breaking of a glass tumbler$
C. $Burning of an incense stick$
D. $Magnetizing a piece of iron$
6.
$What happens to the total mass of substances involved in a chemical reaction according to the Law of Conservation of Mass?$
A. $It increases$
B. $It decreases$
C. $It remains the same$
D. $It becomes zero$
7.
$The formation of a compound from its constituent elements is always a:$
A. $Physical change$
B. $Chemical change$
C. $Reversible change$
D. $Periodic change$
8.
$Why is the 'Explosion of Dynamite' considered an irreversible chemical change?$
A. $It releases a huge amount of light and sound.$
B. $New gaseous products are formed with a massive release of energy that cannot be recombined to form dynamite.$
C. $It happens too fast for the human eye to see.$
D. $The mass of the products is less than the mass of the reactants.$
9.
$If you dissolve Ammonium chloride in water in a beaker, the beaker feels cold to the touch. This indicates that:$
A. $A chemical change has occurred which is exothermic.$
B. $A physical change (dissolution) has occurred which is endothermic.$
C. $A chemical change has occurred which is endothermic.$
D. $The substance is a refrigerant.$
10.
$Which of these processes is a 'Thermal Decomposition'?$
A. $Heating Ammonium chloride to get vapors.$
B. $Heating Calcium carbonate to get Lime and Carbon dioxide.$
C. $Heating a glass rod until it bends.$
D. $Heating water until it becomes steam.$

Download the worksheet for Chemistry - Physical and Chemical Changes to practice offline. It includes additional chapter-level practice questions.

Elements, Compounds and Mixtures (Separation Techniques)

Subtopic

Elements, Compounds and Mixtures (Separation Techniques) under Chemistry for Grade 8 ICSE.

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Preview questions (no answers)

1.
$Which of the following methods is used to separate seeds from fruit juice?$
A. $Filtration$
B. $Crystallization$
C. $Sublimation$
D. $Distillation$
2.
$What do we call the liquid that passes through the filter paper during filtration?$
A. $Residue$
B. $Filtrate$
C. $Solvent$
D. $Distillate$
3.
$The process of 'loading' helps in the sedimentation of:$
A. $Heavy sand particles$
B. $Light suspended clay particles$
C. $Dissolved salts$
D. $Floating oil drops$
4.
$Which of these mixtures is best separated by using a separating funnel?$
A. $Alcohol and water$
B. $Petrol and water$
C. $Salt and water$
D. $Sand and water$
5.
$Which of the following techniques is used to obtain pure common salt from sea water on a large scale in coastal areas?$
A. $Crystallization$
B. $Simple distillation$
C. $Evaporation$
D. $Filtration$
6.
$In a saturated solution, no more solute can be dissolved at a given temperature. If we heat this saturated solution, what happens?$
A. $It becomes even more saturated$
B. $More solute can be dissolved in it$
C. $The solute will precipitate out$
D. $The solvent will freeze$
7.
$The method of 'winnowing' is used to separate components of a mixture based on:$
A. $Magnetic properties$
B. $Difference in weight (density) under the influence of wind$
C. $Difference in solubility in water$
D. $Difference in size of particles$
8.
$Which method would you use to separate a mixture of various pigments found in a leaf extract?$
A. $Simple Distillation$
B. $Fractional Distillation$
C. $Chromatography$
D. $Crystallization$
9.
$Why can a mixture of Alcohol and Water not be separated 100% into pure components by simple distillation?$
A. $They form an azeotrope at a certain concentration$
B. $Water boils at a lower temperature than alcohol$
C. $They are immiscible$
D. $Alcohol reacts with water to form a gas$
10.
$Which of these gases is collected at the 'bottom' of a fractional distillation column during the processing of liquid air because it has the highest boiling point?$
A. $Nitrogen$
B. $Oxygen$
C. $Helium$
D. $Neon$

Download the worksheet for Chemistry - Elements, Compounds and Mixtures (Separation Techniques) to practice offline. It includes additional chapter-level practice questions.

Atomic Structure (Protons, Neutrons, Electrons, Valency, Isotopes)

Subtopic

Atomic Structure (Protons, Neutrons, Electrons, Valency, Isotopes) under Chemistry for Grade 8 ICSE.

About Topic & Revision

Preview questions (no answers)

1.
$Which of the following is an example of an isobar pair?$
A. $^{12}C$
B. $^{35}Cl$
C. $^{40}Ar$
D. $^{1}H$
2.
$The chemical properties of an atom are primarily determined by its:$
A. $Number of neutrons$
B. $Valence electrons$
C. $Mass number$
D. $Atomic mass$
3.
$If an element has atomic number 19, how many shells does its atom have?$
A. $2$
B. $3$
C. $4$
D. $5$
4.
$The central part of an atom which contains nearly all its mass is called the:$
A. $Electron cloud$
B. $Shell$
C. $Nucleus$
D. $Orbit$
5.
$Al^{3+}$
A. $10$
B. $13$
C. $16$
D. $3$
6.
$Which of the following is true for an atom that forms an anion?$
A. $It is usually a metal$
B. $It loses electrons$
C. $It is usually a non-metal$
D. $Its number of protons increases$
7.
$If an element has atomic number 20, what is the number of electrons in its outermost shell?$
A. $2$
B. $8$
C. $18$
D. $1$
8.
$An element with atomic number 14 has how many valence electrons?$
A. $2$
B. $4$
C. $6$
D. $8$
9.
$Which of the following subatomic particles determines the chemical properties of an element?$
A. $Neutrons in the nucleus$
B. $Electrons in the outermost shell$
C. $Protons in the nucleus$
D. $Total number of nucleons$
10.
$K, L,$
A. $Atomic number 18, Valency 0$
B. $Atomic number 10, Valency 0$
C. $Atomic number 18, Valency 8$
D. $Atomic number 28, Valency 0$

Download the worksheet for Chemistry - Atomic Structure (Protons, Neutrons, Electrons, Valency, Isotopes) to practice offline. It includes additional chapter-level practice questions.

Language of Chemistry (Symbols, Formulae, Balancing Equations)

Subtopic

Language of Chemistry (Symbols, Formulae, Balancing Equations) under Chemistry for Grade 8 ICSE.

About Topic & Revision

Preview questions (no answers)

1.
$What is the chemical formula for Hydrogen Chloride (Hydrochloric acid gas)?$
A. $HCl$
B. $H_2Cl$
C. $HCl_2$
D. $H_2Cl_2$
2.
$What is the chemical symbol for Manganese?$
A. $Ma$
B. $Mg$
C. $Mn$
D. $Me$
3.
$What is the chemical symbol for Nickel?$
A. $Ni$
B. $N$
C. $Ne$
D. $Na$
4.
$Which of these is the chemical symbol for Cobalt?$
A. $C$
B. $Ca$
C. $Co$
D. $Cr$
5.
$MnO_2$
A. $2$
B. $3$
C. $4$
D. $7$
6.
$Which of these correctly represents the formula for Silver Nitrate?$
A. $SiNO_3$
B. $AgNO_3$
C. $Ag_2NO_3$
D. $Ag(NO_3)_2$
7.
$OH$
A. $+1$
B. $-1$
C. $-2$
D. $+2$
8.
$Pb(NO_3)_2 \rightarrow PbO + NO_2 + O_2$
A. $3$
B. $5$
C. $7$
D. $9$
9.
$What is the formula of 'Ferric Ferrocyanide'?$
A. $Fe_4[Fe(CN)_6]_3$
B. $Fe_3[Fe(CN)_6]_4$
C. $Fe[Fe(CN)_6]$
D. $Fe_2[Fe(CN)_6]$
10.
$xH_2S + ySO_2 \rightarrow zS + wH_2O$
A. $x=1, y=1$
B. $x=2, y=1$
C. $x=1, y=2$
D. $x=2, y=2$

Download the worksheet for Chemistry - Language of Chemistry (Symbols, Formulae, Balancing Equations) to practice offline. It includes additional chapter-level practice questions.

Chemical Reactions (Types of Reactions, Oxides)

Subtopic

Chemical Reactions (Types of Reactions, Oxides) under Chemistry for Grade 8 ICSE.

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Preview questions (no answers)

1.
$Which of the following is an example of a fast chemical reaction?$
A. $Rusting of iron$
B. $Formation of coal$
C. $Burning of a matchstick$
D. $Growth of a plant$
2.
$CaO$
A. $Combination$
B. $Decomposition$
C. $Displacement$
D. $Neutralization$
3.
$In a chemical equation, the substances written on the left side of the arrow are called:$
A. $Products$
B. $Catalysts$
C. $Reactants$
D. $Precipitates$
4.
$What is the product when phosphorus burns in excess of oxygen?$
A. $P_2O_3$
B. $P_4O_{10}$
C. $PO_2$
D. $P_2O_5$
5.
$ZnCO_3$
A. $It is black when hot and remains black upon cooling.$
B. $It is yellow when hot and turns white upon cooling.$
C. $It is white when hot and turns yellow upon cooling.$
D. $It is green when hot and turns blue upon cooling.$
6.
$When aqueous solutions of Lead Nitrate and Potassium Iodide are mixed together, a double displacement reaction occurs as shown in the diagram. A characteristic bright yellow precipitate 'X' is formed. What is the chemical formula of this precipitate?$
A. $KNO_3$
B. $PbI_2$
C. $PbI$
D. $NO_2$
7.
$When blue Copper sulphate crystals are heated strongly, they turn into a white anhydrous powder. What is the formula of this white powder?$
A. $CuSO_4$
B. $Cu(OH)_2$
C. $CuO$
D. $CuSO_4 \cdot 5H_2O$
8.
$What is the observation when Hydrogen gas is passed over heated black Copper(II) Oxide?$
A. $A blue solution is formed$
B. $The black oxide turns into a reddish-brown metal$
C. $No change occurs as Hydrogen is less reactive than Copper$
D. $A yellow residue is left behind$
9.
$SiO_2$
A. $P_2O_5$
B. $CO_2$
C. $CaO$
D. $SO_3$
10.
$2KI + Cl_2 \rightarrow 2KCl + I_2$
A. $A reducing agent because it gains electrons$
B. $An oxidizing agent because it gains electrons$
C. $A reducing agent because it loses electrons$
D. $An oxidizing agent because it loses electrons$

Download the worksheet for Chemistry - Chemical Reactions (Types of Reactions, Oxides) to practice offline. It includes additional chapter-level practice questions.

Hydrogen (Preparation, Properties, Uses)

Subtopic

Hydrogen (Preparation, Properties, Uses) under Chemistry for Grade 8 ICSE.

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Preview questions (no answers)

1.
$What is the symbol used for the element Hydrogen?$
A. $He$
B. $Hy$
C. $H$
D. $Hg$
2.
$Which of these acids will NOT produce hydrogen when reacted with zinc?$
A. $Dilute sulfuric acid$
B. $Dilute hydrochloric acid$
C. $Concentrated nitric acid$
D. $Dilute phosphoric acid$
3.
$PbO + H_2 \rightarrow Pb + H_2O$
A. $H_2$
B. $PbO$
C. $Pb$
D. $H_2O$
4.
$During the electrolysis of acidified water, hydrogen gas is collected at the:$
A. $Anode$
B. $Cathode$
C. $Surface of the water$
D. $Bottom of the container$
5.
$Which of these pairs of reactants will NOT yield hydrogen gas?$
A. $Iron and dilute hydrochloric acid$
B. $Copper and dilute sulfuric acid$
C. $Zinc and sodium hydroxide$
D. $Magnesium and steam$
6.
$CaH_2$
A. $+1$
B. $-1$
C. $0$
D. $+2$
7.
$Hydrogen gas is collected in the lab by the downward displacement of water because it is nearly insoluble in water. What other method can be used for its collection based on its density?$
A. $Upward displacement of air$
B. $Downward displacement of air$
C. $Upward displacement of mercury$
D. $Downward displacement of mercury$
8.
$A student investigated the reaction of magnesium metal with water in two different states as shown in the flowchart. Based on the rules of metal reactivity and the temperature of the reactants, which of the following correctly identifies the chemical nature of the solid products X and Y?$
A. $MgO$
B. $Mg(OH)_{2}$
C. $MgO$
D. $Mg(OH)_{2}$
9.
$Why is the reaction between calcium and cold water less violent than the reaction between sodium and cold water?$
A. $Calcium is more electropositive than sodium$
B. $The heat evolved is not sufficient to melt the calcium or ignite the hydrogen$
C. $Calcium forms a protective oxide layer immediately$
D. $Sodium is a transition metal while calcium is not$
10.
$In the reduction of metallic oxides by hydrogen, what is the role of the hydrogen gas?$
A. $It acts as an oxidizing agent$
B. $It acts as a catalyst$
C. $It acts as a reducing agent$
D. $It acts as a flux$

Download the worksheet for Chemistry - Hydrogen (Preparation, Properties, Uses) to practice offline. It includes additional chapter-level practice questions.

Water (Hard and Soft Water, Water Pollution)

Subtopic

Water (Hard and Soft Water, Water Pollution) under Chemistry for Grade 8 ICSE.

About Topic & Revision

Preview questions (no answers)

1.
$Which of these chemical compounds is 'Washing Soda'?$
A. $NaHCO_3$
B. $Na_2CO_3 \cdot 10H_2O$
C. $NaOH$
D. $NaCl$
2.
$Which of the following is a major cause of groundwater pollution?$
A. $Rainwater harvesting$
B. $Seepage of chemical fertilizers and pesticides from fields$
C. $Planting trees$
D. $Evaporation of surface water$
3.
$Boiling water is a simple way to:$
A. $Increase permanent hardness$
B. $Remove dissolved oxygen only$
C. $Kill germs and remove temporary hardness$
D. $Convert soft water into hard water$
4.
$Industrial effluents should be __________ before being discharged into water bodies.$
A. $100^{\circ}C$
B. $Treated to remove toxic chemicals$
C. $Mixed with domestic sewage$
D. $Frozen into ice$
5.
$Why does rainwater become 'hard' only after it reaches the ground or flows through soil?$
A. $Rainwater is naturally hard in the clouds$
B. $It dissolves minerals like calcium and magnesium salts from the soil and rocks$
C. $It reacts with nitrogen in the air to become hard$
D. $It loses oxygen as it falls, which makes it hard$
6.
$The use of which of the following in agriculture is a major cause of groundwater pollution?$
A. $Organic manure$
B. $Synthetic fertilizers and pesticides$
C. $Drip irrigation$
D. $Crop rotation$
7.
$Lead poisoning through water pipes can lead to which of the following health issues?$
A. $Damage to the nervous system and kidneys$
B. $Night blindness$
C. $Bone deformities$
D. $Typhoid fever$
8.
$Which of the following is the most effective method for obtaining 'pure' water for laboratory experiments from a sample of hard water?$
A. $Distillation$
B. $Filtration through sand$
C. $Boiling$
D. $Treatment with washing soda$
9.
$The phenomenon of 'Algal Bloom' is mostly associated with an excess of which two elements in water?$
A. $Nitrogen and Phosphorus$
B. $Carbon and Hydrogen$
C. $Sulfur and Iron$
D. $Calcium and Magnesium$
10.
$Which of the following compounds is used for 'disinfecting' well water and is also known as chloride of lime?$
A. $CaOCl_2$
B. $CaCl_2$
C. $Ca(ClO_3)_2$
D. $Ca(OH)_2$

Download the worksheet for Chemistry - Water (Hard and Soft Water, Water Pollution) to practice offline. It includes additional chapter-level practice questions.

Carbon and its Compounds (Allotropes, Carbon Dioxide, Methane)

Subtopic

Carbon and its Compounds (Allotropes, Carbon Dioxide, Methane) under Chemistry for Grade 8 ICSE.

About Topic & Revision

Preview questions (no answers)

1.
$Which of the following substances is used as a moderator in nuclear reactors?$
A. $Diamond$
B. $Graphite$
C. $Coke$
D. $Lampblack$
2.
$Carbon dioxide is an example of an:$
A. $Acidic oxide$
B. $Basic oxide$
C. $Neutral oxide$
D. $Amphoteric oxide$
3.
$Which form of coal is considered the lowest grade and has the least carbon content?$
A. $Anthracite$
B. $Bituminous$
C. $Lignite$
D. $Peat$
4.
$CH_4$
A. $2$
B. $3$
C. $4$
D. $1$
5.
$What is the common use of 'Coke' in the metallurgical industry?$
A. $As a flux to remove impurities$
B. $As a reducing agent to extract metals from their ores$
C. $As a lubricant for moving parts$
D. $To produce carbon dioxide for cooling$
6.
$Which of the following is produced during the destructive distillation of coal?$
A. $Carbon Dioxide and Steam$
B. $Coal gas, Coke, and Coal tar$
C. $Methane and Oxygen$
D. $Sodium carbonate and Calcium chloride$
7.
$CH_{4}$
A. $Addition reaction$
B. $Substitution reaction$
C. $Elimination reaction$
D. $Rearrangement reaction$
8.
$-78^{\circ}C$
A. $The molecules break into atoms and rearrange into a covalent network$
B. $The weak intermolecular forces are overcome by pressure to form a molecular solid$
C. $The carbon atoms form ionic bonds with the oxygen atoms$
D. $The gas molecules undergo polymerization into long chains$
9.
$Which specific property of methane makes it a major contributor to global warming compared to carbon dioxide?$
A. $CO_{2}$
B. $CO_{2}$
C. $CO_{2}$
D. $It depletes the ozone layer directly through its hydrogen atoms$
10.
$CO_{2}$
A. $Formation of ammonium carbonate only$
B. $Precipitation of sodium bicarbonate$
C. $Formation of sodium hydroxide$
D. $Evolution of chlorine gas$

Download the worksheet for Chemistry - Carbon and its Compounds (Allotropes, Carbon Dioxide, Methane) to practice offline. It includes additional chapter-level practice questions.

Chemistry

Matter (Kinetic Molecular Theory)

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Physical and Chemical Changes

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Elements, Compounds and Mixtures (Separation Techniques)

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Atomic Structure (Protons, Neutrons, Electrons, Valency, Isotopes)

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Language of Chemistry (Symbols, Formulae, Balancing Equations)

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Chemical Reactions (Types of Reactions, Oxides)

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Hydrogen (Preparation, Properties, Uses)

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Water (Hard and Soft Water, Water Pollution)

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Carbon and its Compounds (Allotropes, Carbon Dioxide, Methane)

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