Chemical Reactions And Equations

Question 1

It Burns with a white dazzling flame and changes into a white powder

Answer 1

Magnesium when reacting with oxygen in the air

Question 2

Determines if a chemical reaction has taken place

Answer 2

change in state
change in colour
evolution of a gas
change in temperature

Question 3

2Mg + O2

Answer 3

2Mgo

Question 4

The left side of the equation

Answer 4

Reactants

Question 5

The right side of the equation

Answer 5

Products

Question 6

Arrow

Answer 6

The direction of the reaction

Question 7

short representation of a reaction

Answer 7

a chemical equation

Question 8

Zn + H2So4

Answer 8

ZnSo4 + H2

Question 9

an unbalanced equation is also known as

Answer 9

a skeletal equation

Question 10

Fe + H2O

Answer 10

Fe3O4 + H2

Question 11

mass of reactants should equal to the mass of products

Answer 11

law of conservation of mass

Question 12

Method of balancing chemical equations while making trials to balance the equation by using the smallest whole number coefficient

Answer 12

Hit and Trial Method

Question 13

solid present as a solution in water

Answer 13

Aqueous solution

Question 14

CaO

Answer 14

Quick Lime

Question 15

Ca(OH)2

Answer 15

Slaked Lime

Question 16

solution of calcium hydroxide

Answer 16

used for whitewashing walls

Question 17

two or more reactants react to give one product

Answer 17

Combination reaction

Question 18

a reaction where heat is released along with products

Answer 18

Exothermic reaction

Question 19

a reaction where one reactant decomposes to form two or more products

Answer 19

Decomposition reaction

Question 20

When a decomposition reaction is carried out by heating

Answer 20

Thermal Decomposition reaction

Question 21

When light energy like sunlight is used to decompose a reactant

Answer 21

Photolytic Decomposition reaction

Question 22

When electricity is used for the decomposition reaction

Answer 22

Electrolytic Decomposition reaction

Question 23

ferrous sulphate decomposes to

Answer 23

ferric oxide, sulphur dioxide and sulphur trioxide

Question 24

Use of calcium oxide

Answer 24

manufacture cement

Question 25

Nitrogen dioxide

Answer 25

brown fumes

Question 26

white silver chloride turns

Answer 26

grey under sunlight

Question 27

a reaction where energy is absorbed

Answer 27

endothermic reaction

Question 28

the reactions of silver chloride and silver bromide with sunlight are used in

Answer 28

black and white photography

Question 29

iron nail dipped in copper sulphate solution becomes

Answer 29

brownish in color

Question 30

the blue colour of copper sulphate solution fades away

Answer 30

when iron nails are dipped in copper sulfate solution

Question 31

When a higher reactive metal displaces a lesser reactive metal from its solution then it is known as

Answer 31

A displacement reaction

Question 32

insoluble substance formed

Answer 32

precipitate

Question 33

precipitate reaction

Answer 33

any reaction that produces a precipitate

Question 34

reactions where there is an exchange of ions between the reactants

Answer 34

double displacement reaction

Question 35

oxygen is added to copper

Answer 35

a layer of black substance is formed called copper oxide

Question 36

hydrogen gas passed through heated CuO

Answer 36

the reverse reaction takes place and the black coating turns brown again

Question 37

if a substance gains oxygen during a reaction

Answer 37

oxidized substance

Question 38

if a substance loses oxygen during a reaction

Answer 38

reduced substance

Question 39

a reaction where one reactant gets oxidized while the other gets reduced

Answer 39

redox reaction

Question 40

the substance getting oxidized is

Answer 40

a reducing agent

Question 41

the substance getting reduced is

Answer 41

an oxidizing agent

Question 42

oxidized reaction

Answer 42

addition of oxygen or loss of hydrogen

Question 43

reduced reaction

Answer 43

addition of hydrogen or loss of oxygen

Question 44

shiny iron particles get coated with reddish-brown powder

Answer 44

rusting of iron

Question 45

when metal is attacked by other substances in its surroundings like moisture, acids, etc

Answer 45

the process is known to be corrosion

Question 46

when fats and oils are oxidized

Answer 46

they become rancid

Question 47

rancid substances

Answer 47

change their taste and smell

Question 48

substances that prevent oxidation

Answer 48

antioxidants

Question 49

ways to slow down oxidation

Answer 49

keeping food in airtight containers

Question 50

chips manufacturer flush chips bags

Answer 50

with nitrogen in order to prevent them from getting oxidized