Question

balance the following chemical equation and identify the type of reaction they

represent

KClO3

→ KCl + O2

NH3

+ O2

→ NO + H2O​

Answer 1

Answer:

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3 X – Science

CHAPTER – 1

q Chemical Reaction : –Whenever a chemical change occurs we can say that

a chemical reaction has taken place

eg – Food gets digested in our body

– Rusting of iron.

q Chemical Equation :–Achemical reaction can be expressed symbolically

by using chemical equation

eg magnesium is burnt into air to form magnesium oxide can be represented

as

Mg + O2 ®MgO

– We can observe or recognise a chemical reaction by observing change

in state, colour, by evolution of gas or by change in temperature.

q Physical state of the reactant and products are mentioned to make chemical

reaction more informative. eg we use (g) for gas, (l) for liquid, (s) for solid

and (aq) for aqueous.

q Balancing Equation :– We balance the chemical equation so that no. of

atoms of each element involved in the reaction remain same at the reactant

and product side.

eg Fe + H2O ® Fe2O3 + H2 can be written as

3 Fe(s) + 4H2O(g) ® Fe2O3(s) +4H2(g)

q Combination Reaction :– The reaction in which two or more substances

combine to form a new single substance

ChemicalReactionsandEquations

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4 X – Science

eg CaO(s) + H2O(l) ¾¾® Ca(OH)2 (aq)

Calcium Water Calciumhydroxide

oxide (slaked lime)

Quick lime

– Ca(OH)2 slaked lime is used for white washing walls. It reacts will CO2 to

form CaCO3 and gives a shiny finish to the walls.

Ca(OH)2(aq)+ CO2(g)

¾¾® CaCO3(s)+ H2O (l)

Calcium Calcium

hydroxide Carbonate

– Burning of Coal

C(s) + O2(g) ¾¾® CO2(g) + heat + light

– Formation of water

2H2(g) + O2(g) ¾¾® 2H2O(l)

q Exothermic Reactions :– Reaction in which heat is released along with the

formation of products.

eg. CH4(g) + 2O2(g) ¾¾®CO2(g) + 2H2O(g)

– Respiration is also exothermic reaction.

– De composition of vegetable matter into compost.

q De compositon Reactions :– The reaction in which a single substance

decomposes to give two or more substances. De composition reactions can

be of three types

Thermal Decompositon :–When a decompositon reaction is carried out by

heating

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5 X – Science

– Silver bromide behaves similarly

2Ag Br ¾¾Su¾nl¾igh¾t¾® 2Ag(s) + Br2(g)

– The above two reactions are used in black and white photography.

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– Endothermic Reactions – The reactions which require energy in the form

of heat, light or electricty are called Endothermic Reactions.

2Ba(OH)2 + NH4Cl ¾¾® 2BaCl2 + NH4OH

– Displacement Reaction : The chemical Reaction in which an element

displaces another element from its solution

Fe(s) + CuSO4(aq) ¾¾® FeSO4 + Cu(s)

Copper (aq)

Sulphate Iron Sulphate

– The nail becomes brownish in colour and the blue colour of Copper Sulphate

solution fade.

– Other examples Zn(s) + CuSO4 ¾¾® ZnSO4 + Cu(s)

(aq) (aq)

Copper Zinc

Sulphate Sulphate

Pb(s) + CuCl2 ¾¾® PbCl2 + Cu(s)

(aq) (aq)

Copper Lead

Chloride Chloride

– Zinc and lead are more reactive elements than copper. They displace copper

from its compounds.

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– Double Displacement Reaction : The reaction in which two different atoms

or group of atoms are mutually exchanged

eg. Na2 SO4 + BaCl2 ¾¾® BaSO4(s) + 2NaCl

(aq) (aq) (aq)

Sodium Barium Barium Sodium

Sulphate Chloride Sulphate Chloride

A white substance is formed due to above reaction. The insoluble substance

is called precipitate.

Precipitation Reaction –Any reaction that produces a precipitate is called a

precipitation reaction.

eg. Pb(NO3)2 + 2KI ¾¾® PbI2  +2KNO3

(aq) (aq) (aq)

Lead Nitrate Potassium Lead Potassium

Iodide Iodide Nitrate

– Oxidation : Oxidation is the gain of oxygen or loss of hydrogen

eg. 2Cu + O2 ¾¾He¾at¾® 2CuO

When Copper is heated a black colour appears. If this CuO is reacted with

hydrogen gas then again Cu becomes brown as reverse reaction takes place

CuO + H2 ¾¾He¾at¾® Cu + H2O

– Reduction : Reduction is the loss of oxygen or gain of hydrogen.

– Redox Reaction : The reaction in which one reactant gets oxidised while

other gets reduced

eg. ZnO + C ¾¾® Zn + CO

MnO2 + 4HCl ¾¾® MnCl2 + 2H2O + Cl2

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8 X – Science

– Corrosion : When a metal is attacked by substances around it such as

moisture, acids etc.

eg. Reddish brown coating on iron.

(ii) Black coating on Silver.

– Rancidity : When fats and oils are oxidised they become rancid and their

smell and taste change.

– Antioxidants are added to foods containing fats and oil.

Explanation:

and please please please mark me as the brainliest

Answer 2

Answer:

1) 2KClO3 => 2KCl + 3O2

2). 2NH3 + 5/2 O2 => 2NO + 3H2O

Explanation:

1. Decomposition reaction
2. Redox reaction