Popular Chemistry Online

Link ad

Followers

Thursday, January 14, 2021

Acids,bases and salts Quiz-1

Acids, bases and salts

Acids, bases and salts

Quiz

 

Wednesday, January 13, 2021

structure of the atom -Slide show

 

It is the complete slides made on NCERT Class IX Chapter-4 Structure of atom

Tuesday, January 12, 2021

Acids and bases

 

The taste of the food varies because each food item has a unique chemical composition. Based on their chemical nature, substances can be categorized into acids, bases and salts.

Acids:

Acids are compound in which one of the elements that makes up the acid molecule is always the hydrogen   element. For example, hydrochloric acid (HCl).

Substances that contain acids are known as acidic substances. The word acid comes from the Latin word 'acere' meaning sour.

 Types of acids:


Based on the sources they are obtained from, acids are of two types:

A. Organic acids: Acids that are naturally obtained from plants and animal sources are called organic acids.

B. Mineral acids: Acid that are derived from an inorganic material or source are called mineral acids. For example, nitric acid, hydrochloric acid and sulphuric acid.

    Depending upon the amount of water present in acids, they are categorized into concentrated and dilute acids.

A. Concentrated acids: Acids that contain only a small quantity of water are called concentrated acids.

B. Dilute acids: Acids that contain more water than the concentrated acid are called dilute acids. They can be obtained by adding water to a concentrated acid.

Properties of acids:

·   Acids are sour to taste.

·   Acids turns blue Litmus to red.

·    Acids can corrode metals like aluminium and iron due to their corrosive nature. That is why acids are stored in glass containers and not in metal containers.

·    Acids are soluble in water.

Strong acids

Weak acids

 Hydrochloric acid

Sulphuric acid,

 Nitric acid,

 phosphoric acid

  citric acid,

 lactic acid,

Acetic Acid,

 carbonic acid


Acids are widely used in industries and present in everyday products. Hydrochloric acid which is present in our stomach, help to digest our food. Uses of some acids are given in the following tableUses of acids:

Bases:

Bases  are compounds which contain oxygen or oxygen along with hydrogen. A base that contain oxygen is called an oxide while a base that contains oxygen along with hydrogen is called the Hydroxide.

Substances that contain bases are called basic substances.

Types of Bases:

Based on how  they  take  part in a reaction, bases are of two types: strong bases and weak bases.

A. Strong bases: Some of the bases are corrosive in nature and may result in skin burns. Such bases are called strong bases. For example, Sodium hydroxide, calcium hydroxide and potassium hydroxide.

A. Weak bases: Some of the bases are not corrosive in nature. Such bases are called weak bases. For example, Magnesium hydroxide, Ammonium hydroxide, copper hydroxide.

Properties of bases:

·       Bases are bitter to taste.

·       Bases turn red litmus to blue.

·       Some of the bases are soluble in water they are called alkalis (potassium hydroxide and sodium hydroxide).

·       Bases react with acids to form a salt and water.

Uses of bases:

Sodium Hydroxide is a strong base and it is used to drain cleaners. Strong bases dissolve grease and help in removing dirt.

Uses of some bases are given in the following table

Salts

A salt is formed when an acid and a base react.

The reaction in which acids react with bases resulting in the formation of salt and water are called neutralization reactions.

Types of salts:

A salt can be acidic basic or neutral.

Acidic salts: Acidic salt are formed when strong acids react with weak bases. These salts

have    pH   value   of   less    than 7. 

Basic salts: Basic salt are formed when strong Bases react with weak acids. These salts have

pH   value   of   more    than 7. 

 neutral   S   alts- formed by the reaction of strong acids and strong bases or weak acids and weak bases  

General Examples of salts- Ammonium chloride  -    NH4Cl  

aluminium chloride (AlCl3), Sodium chloride -NaCl

Properties of Salts:

·       Most of the salts are soluble in water.

·       Solution of salts in water act as good conductor of electricity.

·       Some salts are white crystal whereas some are colored. For example, copper sulphate is blue in color and ferrous sulphate is green.

Uses of salts

Neutralization reaction:

When the bases react with acid to produce salt and water. This is a neutralization reaction. In a neutralization reaction, the acid loses its acidity and the base its alkalinity. As a result, a neutral solution is obtained.

Uses of neutralization reactions:

Following are some neutralization reaction that we observe in our everyday life.

In the treatment of ant sting: Some people are highly allergic to ant string as it releases formic acid.



It is neutralized by rubbing moist baking soda (sodium bicarbonate) or Calamine solution, which contains zinc carbonate on the affected area.

In the treatment of indigestion: Hydrochloric acid secreted in the stomach helps in the digestion of food. However, its excess secretion could lead to acidity and indigestion. Milk of magnesia is used to neutralize the acid.

In the treatment of soil: When the soil is too acidic, it is treated with slaked lime or quicklime, which is a base. If the soil is too basic, it is treated with organic matter such as fertilizers that are obtained from vegetables or fruits as they are acidic in nature.

In the treatment of sewage waste: several Industries produce acids as waste. If they are allowed to flow into water bodies, these wastages would affect aquatic organisms.

Slaked lime (Calcium Hydroxide) is often used to neutralize this acidic waste let out from the factories.

 Protecting teeth: One of the best common applications of neutralization of acids is the toothpaste. Toothpastes contain an alkali that neutralizes the weak acid produced by bacteria and prevent tooth damage.

Lucent's General Knowledge: Free Download and reading Lucent GK Book 2020

Lucent's General Knowledge: Download Free Lucent GK Book 2020

Lucent's General Knowledge: Download Free Lucent GK Book 2020 

It is most popular book among students those who are doing preparation of SSC,PCS, Bank Clerk, Bank PO etc. i am sharing here its Hindi version, so you can download it at free of cost can read online
Click here to download it as pdf

Monday, January 11, 2021

Conservation of plants and animals

      Deforestation and its causes:

The variety of plants and animals existing on earth are essential for the well being and survival of mankind. Today a major threat to survival of mankind is deforestation.

Deforestation means clearing of forests and using that land for other purposes, i.e. for industries set up or making building for rehabitation. 

The causes of deforestation may be:

-  Procuring land for cultivation.

- Building houses and factories.

-  Making furniture, using wood as fuel and

-  Natural causes such forest fires and draughts.

      Effects of deforestation:

  - Deforestation causes increase of atmospheric temperature due to increase in concentration of carbon dioxide leading to global warming, Severe draughts and floods. 

 - Deforestation changes the nature of soil, water holding capacity and soil erosion. Gradually, the fertile land gets converted into deserts. It is called desertification.

 Deforestation causes the destruction of habitat of wildlife, its survival becomes difficult.

     Biosphere: The part of the earth in which living organisms exist or that supports life is known as biosphere.

     Biodiversity or Biological diversity: It refers to the variety or organisms existing on the earth. Their interrelationships and their relationship with the environment. It includes variety of plants, animals and microorganisms.

     Flora and Fauna: The plants found in a particular area are termed as flora area. The animals found in a particular area are termed as fauna of that area.

     Endemic Species: Those species of plants arid animals which are found exclusively in a particular area are called endemic species to a zone, a state or a country. For example, sal and wild mango endemic flora of the Pachmarhi Biosphere Reserve. Animals such as Bison, Indian giant squirrel and fly squirrel are endemic fauna of this area.


     Species: A group of population or populations whose members have common characteristics and are capable of interbreeding among themselves to produce fertile off-springs. Normally, members of a species breed amongst themselves and not with members of other species

     National parks, sanctuaries and biospheres reserves are maintained to conserve forests and wildlife.

     Biosphere Reserve: AA larger protected area meant for conservation of biodiversity and culture of that area is called Biosphere Reserve. A biosphere may consists of other protected areas such as National Parks and Sanctuaries. For example, Pachmarhi Biosphere Reserve consists of one National Park called Satpura and two Wildlife Sanctuaries known as Bori and Pachmarhi.

     Wildlife Sanctuaries: These are the protected areas which provide protection and suitable living conditions to wild animals. Sanctuaries are places where killing (poaching) or capturing of animals is strictly prohibited.

A sanctuary may be a reserved natural area meant for the preservation and development of threatened/endangered species. For example, there is the Kaziranga Wildlife Sanctuary for Rhinoceros in Assam.


     National Park: A national park reserve is large and diverse enough to protect whole set of ecosystem. National Parks preserve flora, fauna, landscape and historic objects of an area. For example. In the Satpura National Park, Rock shelters and Rock paintings are also preserved along with flora and fauna.

 

     Endangered Animals: Animals whose numbers are diminishing to a level that they might face extinction are known as the endangered animals. For example, dinosaurs became extinct a long time ago.

     Ecosystem: All the living components, such as plants, animals and microorganisms and non-living components such as climate, soil, river, deltas etc. constitute an ecosystem. An ecosystem can be as small as a pond or as big as an ocean or a forest.

     Red Data Book: The source book which keeps a record of all the endangered animals and plants. There are different Red Data Books.

     Migration: The phenomenon of movement of a species from its own habitat to some other for a particular time period every year for a specific purpose like breeding is known as migration.

     Reuse and recycling of paper save trees, energy and water.

     Reforestation is restocking of the destroyed forests by planting new trees.

feature post

CARBON AND ITS COMPOUNDS-Functional Group

1. Name the functional groups present in the following compounds. a)     CH 3  – CO –CH 2 –CH 2  –CH 2 –CH 3 b)    CH...