Explore topic-wise InterviewSolutions in Current Affairs.

(D) soap micelles scatter light

Acetic acid.

The answer is (c) 16 covalent bonds

Sixteen (16) Covalent bonds.

Uses of Ethanoic acid

• Ethanoic acid is used in the manufacture of dyes, perfumes and rayons

• Manufacture of rubber from latex and casein from milk. It is used for coagulation.

• In the form of salts in medicine and paints.

• In the form of acetates of aluminium and chromium is used as mordants.

• In dilute form is used as vinegar and in the concentrated form as a solvent.

• In form of organic esters as perfumes.

The answer is (c)

• Chemical formula of Benzene is C₆H₆. 
• In option call the arms of carbon atoms are occupied hence it is the right answer.

Ethanoic acid is used as a preservative in pickles. 

It is also used in the production of esters which are used in making perfumes and as flavouring agents.

The molecules of soap are sodium or potassium salts of long-chain carboxylic acids.

Concentrated sulphuric acid acts as dehydrating agent i.e., removes water molecule from ethanol and also catalyse the reaction and convert ethanol to ethane.

Rutherford’s Model of atom : This model was based upon the results of the famous alpha-rays scattering experiment. It is also known as ‘Planetary model’ and can be summarised in following points.

(i) Most of the mass and all the positive charge of an atom are present in a very small region called the nucleus.

(ii) The magnitude of the charge on the nucleus is different in atoms of different elements.

(iii) Electrons revolve in the space around nucleus in different circular orbits and the number of electrons is equal to the number of units of positive charge in the nucleus.

(a) Salt: NaCl is added while making soap, because it will help the reaction to occur faster and adds sodium ion to increase the reaction rate. 

(b) In test tube A: Soap + Oil ⎯→ Lather/foam is formed. Carboxylic chain dissolves in oil. 

In test tube B: Soap + Hard water ⎯→ Insoluble compound called scum is formed. 

In test tube C: Soap + soft water ⎯→ Froth is formed. 

(c) Yes, we can use potassium hydroxide to prepare soap

They mistook a dead whale sperm to be an island from a distance as it was so huge.

In situ conservation measures will help larger number of species to survive because this approach involves protection of species in their natural habitat, e.g., national parks, sacred groves, biodiversity hot spots, etc.

Since, Atomic number = Number of protons = Number of electrons

Therefore,

Number of electrons in calcium = 20

Number of protons in calcium = 20

(i) The trait is sex-linked.

(ii) Haemophilia, Colour blindness

Mass number is always equal to the number of protons plus the number of
neutrons and Atomic number is always equal to the number of protons which is equal to
the number of electrons to maintain the neutrality of the atom.

Hence, option D is correct.

Rutherford’s atomic model has the following features: -

i. There is a positively charged centre in an atom called the nucleus. Nearly all the mass
of an atom resides inside the nucleus.

ii. The electrons revolve around the nucleus in well-defined orbits which can be
compared to solar system.

iii. The size of the nucleus is very small as compared to the size of an atom.

Hence, statement I and iii are correct t.

So, the correct option is A.

• An atom has a center called nucleus 
• Compared to the size of an atom the size of the nucleus is very smell 
• All the positively charged particles and most of the mass are concentrated in the nucleus of atoms.
• Negatively charged electrons revolve around the nucleus in circular path. 
• This atom model is known as planetary model of atom because sun at the center is compared to the nucleus planets revolving around the sun is compared to electrons.

Rutherford’s nuclear model of an atom: -

i. There is a positively charged center in an atom called the nucleus. Nearly all the mass of an atom resides inside the nucleus.

ii. The electrons revolve around the nucleus in well-defined orbits.

iii. The size of the nucleus is very small as compared to the size of an atom.

Crushing can experiment: When a can filled with hot water is closed and is cooled down rapidly by pouring cold water on it, it will crush instantly. This experiment proves that there is a huge atmospheric pressure exerts on everything on the surface of the earth.

Forests help in rainfall. Therefore droughts do not occur frequently.

1. Drinking Straw works on atmospheric pressure 

2. Vacuum Cleaner works on atmospheric pressure.

The earth’s interior is divided into three main layers — the crust is the outermost layer, the mantle is the intermediate layer, and the core is the innermost layer of the earth.

1. Drinking Straw 

2. Vacuum Cleaner

Minerals are natural inorganic substances having a crystalline form with definite physical and chemical properties whereas rocks are made up of a combination of different minerals compacted together. There are about 2,000 minerals in the earth’s crust and these combine differently to form various kinds of rocks.

Rubber sucker a device used in toys, sunlight blocker – suction cups, suction clamps and various other places where “sticking” is required for temporary period and when you don’t want to use glue.

The principle on which Rubber suckers work: When the sucker is pressed against the surface, it squeeze out the air that is behind it. The atmospheric pressure on the outside of the sucker holds its rim firmly against the smooth surface.

Rocks such as marble and granite are used in construction industries. They are cut into stones and are used for building houses, dams, roads, etc. Rocks also provide raw materials such as limestone and gypsum used in the manufacturing of cement.

At higher altitude the atmospheric pressure decreases therefore the blood vessels exceed the outside pressure which causes blood vessels to get rupture.

Sedimentary rocks are formed from sediment accumulated over long periods, usually under water on the floors of shallow seas, rivers, and lakes. These rocks are fromed by the process of evaporation of water containing in limestone which becomes marble.

Metamorphic rocks are those rocks which are formed by the metamorphism of pre-existing rocks due to high temperature or pressure or both. Igneous and sedimentary rocks completely changes over long periods of time because of movements in the earth’s crust and volcanic or mountain building activity. Transformation of rocks due to high temperature is called thermal metamorphism. Alteration of parent rock due to pressure exerted on rocks from the earth’s movements is called dynamic metamorphism.

Thandi’s brother could not be friends with a chicken because he was not able to understand animals. He shouts at chickens and they run away from him.

Thandi snatches a feather very quickly when the chicken is distracted and does not notice.

The two hopes are : 

(1) her name which means hope and 

(2) At the end of the story she can say ‘Good-bye friend’, not ‘Good-bye stranger-friend’.

The clothing of Ndebele women is made of beads. They shine like stars while dancing.

i) They paint their houses with colourful and intricate patterns. 

ii) They make good things with beads. 

iii) They perform their household chores with love and affection.

iv) They respect their ancestors and follow their tradition strictly.

Thandi is a girl who belongs to the tribe of Ndebele from Zimbabwe and northeastern South Africa. Thandi’s best friend is her chicken.

The points to be kept in mind while painting are: 

(1) You have to have strong eyes to paint well. 

(2) Your hand must not shake like leaf on a tree 

(3) You must fill a chicken’s feather with paint and draw a line as straight as a spear. 

(4) You must have the pattern inside your head, even before you dip the feather into the paint

I wear new dress brought by my father on the occasion of my birthday.a

I find those pictures in the exhibitions and in the shops located in pilgrimage places.

Because they live in a different world. They live away from common people.

The villagers decora their houses with different colours during festivals. Most of them use dark colours which bring life to the painting. They paint the pictures of deities, some designs, circles, symbols, etc. on the walls of their houses and celebrate the festivals happily.

I would like to wear specially designed clothes of different colours on special occasions.

Amith is my best friend. He is honest and a true friend of mine. The characteristics such as reliability, honesty, kindness, individuality, helping nature, patience, generosity, trust, etc. make a person a good friend.

Thandi says that her best friend is her chicken. The chicken listens to her stories. Her feathers are used as brushes to paint. She always spends her time with Thandi. Thandi takes her in her arms and tells her many things.

We can draw pictures of birds, moon, stars, sun, sky, all the things related to nature, different designs and a number of other things with a feather.

Our village is Machayapalem of Bellamkonda Madal, Guntur district. It is a picturesque village with narrow streets. Greenery is found everywhere. We have all kinds of animals as pets such as cats, dogs, cows, buffaloes, oxen, goats, sheep, hens, cocks, etc. in our village. Most of us live in thatched houses. Our villagers are friendly in nature. Most of them are farmers. Though we lead an ordinary life, we are always happy. We come together and celebrate the festivals. I love to live in my village.

My name is Nageswara Rao. It has a special meaning. Two Hindu deities are there in my name. ‘Naga’ means ‘Naga Devatha’ and ‘Eswara’ means ‘Lord Parameshwara’.