1. CHEMICAL REACTIONS-MCQ’S-1

Select the option that best matches the chapter's description of products definition. Select the option that best matches the chapter's description of products definition.

1 Mark(s)

When fats and oils are oxidised, they become rancid and their smell and taste change.
The new substances formed during a chemical reaction are called products.
The balanced equation is 2HNO3 + Ca(OH)2 → Ca(NO3)2 + 2H2O.
The balanced form of Fe + H2O → Fe3O4 + H2 is 3Fe + 4H2O → Fe3O4 + 4H2.

According to the NCERT chapter, which of the following is true about chemical reaction indicator? According to the NCERT chapter, which of the following is true about chemical reaction indicator?

1 Mark(s)

The chapter describes balancing by making trials with the smallest whole-number coefficients as the hit-and-trial method.
Respiration is exothermic because glucose combines with oxygen in body cells and provides energy.
A chemical reaction may be indicated by a change in state, colour, evolution of a gas, or change in temperature.
Decomposition reactions of silver chloride and silver bromide in sunlight are used in black and white photography.

Which statement correctly describes reactants definition according to the chapter? Which statement correctly describes reactants definition according to the chapter?

1 Mark(s)

The chemical formula of marble is also CaCO3.
Decomposition reactions of silver chloride and silver bromide in sunlight are used in black and white photography.
In a double displacement reaction, two different atoms or groups of atoms (ions) are exchanged between reactants.
The substances that undergo chemical change are called reactants.

According to the NCERT chapter, which of the following is true about reactants definition? According to the NCERT chapter, which of the following is true about reactants definition?

1 Mark(s)

Calcium oxide formed from limestone decomposition is called quick lime and is used in cement manufacture.
The substances that undergo chemical change are called reactants.
Pb + CuCl2 → PbCl2 + Cu is a displacement reaction.
Corrosion occurs when a metal is attacked by substances around it such as moisture or acids.

Select the option that best matches the chapter's description of word equation magnesium. Select the option that best matches the chapter's description of word equation magnesium.

1 Mark(s)

The symbol (l) denotes the liquid state.
The word equation is Magnesium + Oxygen → Magnesium oxide.
Calcium hydroxide reacts slowly with carbon dioxide in air to form calcium carbonate, giving a shiny finish after two to three days.
In electrolysis of water, carbon electrodes are connected to a 6 volt battery and dilute sulphuric acid is added.

According to the NCERT chapter, which of the following is true about word equation magnesium? According to the NCERT chapter, which of the following is true about word equation magnesium?

1 Mark(s)

Mg + O2 → MgO is a skeletal equation for burning magnesium because the numbers of oxygen atoms are unequal.
A combination reaction forms a single product from two or more reactants.
The word equation is Magnesium + Oxygen → Magnesium oxide.
A decomposition reaction involves a single substance breaking down to give two or more substances.

Select the option that best matches the chapter's description of chemical reaction indicator. Select the option that best matches the chapter's description of chemical reaction indicator.

1 Mark(s)

Temperature, pressure, or a catalyst may be indicated above and/or below the reaction arrow.
Calcium hydroxide reacts slowly with carbon dioxide in air to form calcium carbonate, giving a shiny finish after two to three days.
2AgBr → 2Ag + Br2 occurs in sunlight. 2AgBr → 2Ag + Br2 occurs in sunlight.
A chemical reaction may be indicated by a change in state, colour, evolution of a gas, or change in temperature.

Which statement correctly describes word equation magnesium according to the chapter? Which statement correctly describes word equation magnesium according to the chapter?

1 Mark(s)

Physical states are included to make a chemical equation more informative; they are not always necessary unless needed to specify them.
On heating ferrous sulphate crystals, their green colour changes and the characteristic odour of burning sulphur can be noticed.
A displacement reaction occurs when an element displaces another element from its compound.
The word equation is Magnesium + Oxygen → Magnesium oxide.

Which statement correctly describes product side according to the chapter? Which statement correctly describes product side according to the chapter?

1 Mark(s)

Mixing sodium sulphate and barium chloride gives a white insoluble precipitate of barium sulphate.
Corrosion occurs when a metal is attacked by substances around it such as moisture or acids.
The displacement in silver recovery is represented by Cu + 2AgNO3 → Cu(NO3)2 + 2Ag.
Products are written on the right-hand side of a chemical equation, with a plus sign between multiple products.

Select the option that best matches the chapter's description of product side. Select the option that best matches the chapter's description of product side.

1 Mark(s)

Rusting is the common name for corrosion of iron, producing a reddish-brown coating.
Dilute hydrochloric acid added to iron filings produces hydrogen gas and an iron chloride salt.
The word equation is Magnesium + Oxygen → Magnesium oxide.
Products are written on the right-hand side of a chemical equation, with a plus sign between multiple products.

Select the option that best matches the chapter's description of reactants definition. Select the option that best matches the chapter's description of reactants definition.

1 Mark(s)

Decomposition reactions require energy in the form of heat, light, or electricity to break down reactants.
A precipitate is an insoluble substance formed during a reaction in solution.
The substances that undergo chemical change are called reactants.
When magnesium burns in air to form magnesium oxide, magnesium gains oxygen and is oxidised.

According to the NCERT chapter, which of the following is true about arrow meaning? According to the NCERT chapter, which of the following is true about arrow meaning?

1 Mark(s)

In a word equation, the arrow points towards the products and shows the direction of the reaction.
A combination reaction forms a single product from two or more reactants.
Decomposition carried out by heating is called thermal decomposition.
Iron displaces copper from copper sulphate because iron is more reactive than copper in the context of the reaction.

Which statement correctly describes arrow meaning according to the chapter? Which statement correctly describes arrow meaning according to the chapter?

1 Mark(s)

The balanced equation is 2NaOH + H2SO4 → Na2SO4 + 2H2O.
A balanced chemical equation has the same number of atoms of each element on the reactant and product sides.
Calcium hydroxide is called slaked lime.
In a word equation, the arrow points towards the products and shows the direction of the reaction.

Select the option that best matches the chapter's description of magnesium observation. Select the option that best matches the chapter's description of magnesium observation.

1 Mark(s)

Burning magnesium ribbon produces a dazzling white flame and a white powder of magnesium oxide.
Milk left at room temperature in summer, fermentation of grapes, cooking, digestion, and respiration involve chemical changes.
The balanced equation is 2HNO3 + Ca(OH)2 → Ca(NO3)2 + 2H2O.
The law of conservation of mass states that mass can neither be created nor destroyed in a chemical reaction.

Which statement correctly describes chemical reaction indicator according to the chapter? Which statement correctly describes chemical reaction indicator according to the chapter?

1 Mark(s)

A chemical reaction may be indicated by a change in state, colour, evolution of a gas, or change in temperature.
Reactants are written on the left-hand side of a chemical equation, with a plus sign between multiple reactants.
Physical states are included to make a chemical equation more informative; they are not always necessary unless needed to specify them.
Decomposition of vegetable matter into compost is cited as another example of an exothermic reaction.

According to the NCERT chapter, which of the following is true about formula representation? According to the NCERT chapter, which of the following is true about formula representation?

1 Mark(s)

Burning magnesium ribbon produces a dazzling white flame and a white powder of magnesium oxide.
Chemical equations are more concise when chemical formulae are used instead of words.
The balanced form of Fe + H2O → Fe3O4 + H2 is 3Fe + 4H2O → Fe3O4 + 4H2.
Formation of water is represented by 2H2 + O2 → 2H2O.

Which statement correctly describes reactant side according to the chapter? Which statement correctly describes reactant side according to the chapter?

1 Mark(s)

Reactants are written on the left-hand side of a chemical equation, with a plus sign between multiple reactants.
Respiration is exothermic because glucose combines with oxygen in body cells and provides energy.
Decomposition reactions of silver chloride and silver bromide in sunlight are used in black and white photography.
In the barium sulphate reaction, SO4^2− and Ba2+ react to form white BaSO4, while sodium chloride remains in solution.

Which statement correctly describes formula representation according to the chapter? Which statement correctly describes formula representation according to the chapter?

1 Mark(s)

Aluminium reacts with copper chloride to form aluminium chloride and copper.
A balanced chemical equation has the same number of atoms of each element on the reactant and product sides.
A reaction in which heat is released along with the products is called exothermic.
Chemical equations are more concise when chemical formulae are used instead of words.

Select the option that best matches the chapter's description of magnesium cleaning. Select the option that best matches the chapter's description of magnesium cleaning.

1 Mark(s)

The chapter asks why the amount of gas collected in one test tube is double that in the other and identifies the gas as hydrogen.
2Cu + O2 → 2CuO represents oxidation of copper on heating.
During a chemical reaction, atoms of one element do not change into atoms of another element, and atoms do not disappear or appear from elsewhere.
A magnesium ribbon is cleaned by rubbing it with sandpaper before burning.

Select the option that best matches the chapter's description of arrow meaning. Select the option that best matches the chapter's description of arrow meaning.

1 Mark(s)

While balancing an equation, the formulae of the compounds or elements must not be altered.
CaO + H2O → Ca(OH)2 + heat; calcium oxide reacts vigorously with water and releases a large amount of heat.
In a word equation, the arrow points towards the products and shows the direction of the reaction.
Ferrous sulphate crystals are FeSO4·7H2O and lose water when heated before decomposing.

According to the NCERT chapter, which of the following is true about magnesium cleaning? According to the NCERT chapter, which of the following is true about magnesium cleaning?

1 Mark(s)

2AgCl → 2Ag + Cl2 occurs in sunlight. 2AgCl → 2Ag + Cl2 occurs in sunlight.
Pb + CuCl2 → PbCl2 + Cu is a displacement reaction.
A magnesium ribbon is cleaned by rubbing it with sandpaper before burning.
In CuO + H2 → Cu + H2O, hydrogen gains oxygen and is oxidised.

Select the option that best matches the chapter's description of reactant side. Select the option that best matches the chapter's description of reactant side.

1 Mark(s)

White silver chloride turns grey in sunlight.
A precipitate is an insoluble substance formed during a reaction in solution.
Reactants are written on the left-hand side of a chemical equation, with a plus sign between multiple reactants.
A green coating on copper is given as an example of corrosion.

According to the NCERT chapter, which of the following is true about product side? According to the NCERT chapter, which of the following is true about product side?

1 Mark(s)

2Cu + O2 → 2CuO represents oxidation of copper on heating.
Products are written on the right-hand side of a chemical equation, with a plus sign between multiple products.
During a chemical reaction, atoms of one element do not change into atoms of another element, and atoms do not disappear or appear from elsewhere.
The substances that undergo chemical change are called reactants.

Which statement correctly describes magnesium cleaning according to the chapter? Which statement correctly describes magnesium cleaning according to the chapter?

1 Mark(s)

Ferrous sulphate crystals are FeSO4·7H2O and lose water when heated before decomposing.
An iron nail dipped in copper sulphate solution becomes brownish while the blue colour of copper sulphate fades.
A magnesium ribbon is cleaned by rubbing it with sandpaper before burning.
In ZnO + C → Zn + CO, carbon is oxidised to CO and ZnO is reduced to Zn.

According to the NCERT chapter, which of the following is true about magnesium observation? According to the NCERT chapter, which of the following is true about magnesium observation?

1 Mark(s)

Burning magnesium ribbon produces a dazzling white flame and a white powder of magnesium oxide.
A black coating on silver is given as an example of corrosion.
Aluminium reacts with copper chloride to form aluminium chloride and copper.
A balanced chemical equation has the same number of atoms of each element on the reactant and product sides.

According to the NCERT chapter, which of the following is true about reactant side? According to the NCERT chapter, which of the following is true about reactant side?

1 Mark(s)

The chapter gives 2FeSO4 → Fe2O3 + SO2 + SO3 on heating.
Reactants are written on the left-hand side of a chemical equation, with a plus sign between multiple reactants.
In electrolysis of water, carbon electrodes are connected to a 6 volt battery and dilute sulphuric acid is added.
Na2SO4 + BaCl2 → BaSO4 + 2NaCl is the precipitation reaction given in the chapter.

Select the option that best matches the chapter's description of formula representation. Select the option that best matches the chapter's description of formula representation.

1 Mark(s)

CaO + H2O → Ca(OH)2 + heat; calcium oxide reacts vigorously with water and releases a large amount of heat.
Heating lead nitrate produces brown fumes of nitrogen dioxide.
Chemical equations are more concise when chemical formulae are used instead of words.
The chapter states that zinc and lead are more reactive elements than copper and can displace copper from its compounds.

Which statement correctly describes magnesium observation according to the chapter? Which statement correctly describes magnesium observation according to the chapter?

1 Mark(s)

When hydrogen is passed over heated CuO, the black coating turns brown and copper is obtained.
Burning magnesium ribbon produces a dazzling white flame and a white powder of magnesium oxide.
Chips manufacturers flush bags with nitrogen to prevent the chips from being oxidised.
NaCl + AgNO3 → AgCl + NaNO3 is a double displacement reaction producing AgCl.

Which statement correctly describes products definition according to the chapter? Which statement correctly describes products definition according to the chapter?

1 Mark(s)

Oxidation is gain of oxygen or loss of hydrogen.
Chips manufacturers flush bags with nitrogen to prevent the chips from being oxidised.
A magnesium ribbon is cleaned by rubbing it with sandpaper before burning.
The new substances formed during a chemical reaction are called products.

According to the NCERT chapter, which of the following is true about products definition? According to the NCERT chapter, which of the following is true about products definition?

1 Mark(s)

In MnO2 + HCl → MnCl2 + H2O + Cl2, HCl is oxidised to Cl2 and MnO2 is reduced to MnCl2.
The new substances formed during a chemical reaction are called products.
During a chemical reaction, atoms of one element do not change into atoms of another element, and atoms do not disappear or appear from elsewhere.
A chemical reaction may be indicated by a change in state, colour, evolution of a gas, or change in temperature.

1. CHEMICAL REACTIONS-MCQ’S-1 : Question 1 of 30