Explore topic-wise InterviewSolutions in Current Affairs.

A. Solution of CO₂ gas in water

C. Both A and B

Answer is (C) Molality

Correct Answer is:C. Molality 

Whereas Molality will not be affected by temperature because it depends on the mass. Even if the volume will change, the mass of solute or solvent in the solution will remain the same. Thus, we can conclude that molality will not be affected by temperature.

The Correct option is C. Molality

A. Dumb-bell

The Correct option is B. Insects

Correct Answer is: A. Double salt 

Potash alum is a double salt of potassium sulphate and aluminium sulphate. It has the formula K₂SO₄. Al₂ (SO₄)₃ .24H₂O.

Correct Answer is: B. Insects 

In nature insects have the highest number of species (30 million). Fungi have 100,000, angiosperms have 260000 and birds have 10,000 species.

Correct Answer is: A. Dumb-bell 

A p orbital has the approximate shape of a pair of lobes on opposite sides of the nucleus, or a somewhat dumbbell shape. An electron in a p orbital has equal probability of being in either half.

Correct Answer is :(b) 1.0 M Na₂SO₄ 

1.0 M Na₂SO₄ is correct because its molecular mass is highest among all that's why its boiling point will be highest among four.

Desorption:-

The process of removing on absorbed substance from the surface on which it is adsorbed is called desorption.

Shape-Selective catalyst:-

The catalyst which depends upon the pore structure of the catalyst and Molecular size of reactant and product Molecules is called shape-selective catalyst e.g. Zeolites.

Correct option is D) 65

(a) Hydrogen 

(b) Oxygen 

(c) Nitrogen 

(d) Carbondioxide

Correct option is A) sulphur

Nitrogen cycle helps to maintain the level of nitrogen in the atmosphere stable. During lightning nitrogen in the atmosphere combines with oxygen and forms nitric oxide. This nitric oxide combines with oxygen again to form nitrogen dioxide Nitrogen dioxide in the presence of oxygen dissolves in rainwater and reaches earth as nitric acid. This nitric acid combines with compounds present in earth and changes them to nitrates. Plants absorb this nitrates easily. Through plant products, nitrogen reacts animals also When plants and animals decay nitrogen again reaches the atmosphere this process goes on continuously. So the amount of nitrogen is kept constant.

• In production of nitrogenous fertilizers 
• To fill in the tyres of vehicles
• Liquified nitrogen as a refrigerant 
• Tc avoid the presence of oxygen in packed foods 
• In the manufacture of ammonia

During lightening the triple bond in nitrogen breaks and combine with the atmospheric oxygen to form nitric oxide (NO)

N₂ + O₂ → 2NO

Nitric oxide thus formed further combines with more amount of oxygen to form nitrogen dioxide (NO₂)

2NO + O₂ → 2NO₂

Nitrogen dioxide dissolves in rainwater in the presence of oxygen and reaches the soil as nitric acid (HNO₃)

4NO₂ + 2H₂O + O₂ → 4HNO₃

Nitric acid reacts with the minerals in the soil to form nitrate salts which is absorbed by the plants. So it is said that lightning is a boom to plants.

Correct option: (A) AB

Hence, the simplest formula of the compound is AB.

Correct option: (C) 40

∵ 40 gm NaOH contains 16 gm of oxygen

∴ 100 gm of NaOH contains \(\cfrac{16}{40}\)  x 100 = 40% oxygen.

Correct answer is 1.605 g

1. The given temperature v/s time graph demonstrates the behaviour of water when heated continuously and uniformly.

2. Line segment AB indicates temperature of ice remaining constant at 0 °C for certain period of time.

• This means, amount of heat (latent heat of fusion) supplied to ice is entirely used for changing its state from solid to liquid.
• Thus, line segment AB denotes conversion of ice at 0 °C into water at 0 °C.

3. Line segment BC indicates continuous rise in temperature of water from 0 °C to 100 °C.

• At point C, boiling point of water is reached and heat energy (latent heat of vaporisation) supplied further is used to convert water into steam.
• During this transformation, temperature remains unchanged as represented by line segment CD.
• Thus, line segment CD denotes conversion of water at 100 °C into steam at 100 °C.

4. Beyond point D, thermometer again shows rise in temperature.

The process of coating of a layer of any metal over other metal is called electroplating. The purpose of electroplating is to provide the shiny appearance, rust free metal surface etc.

Example 

1. Chromium plating is done on metals body parts of cars, bikes, cycles, etc. 

2. Gold and silver plating is done on the artificial jewelry

The stationary phase is selected in such a way that the impurities are more strongly absorbed or are more soluble in the stationary phase than element to be purified. Under these conditions, when the column is extracted, the impurities will be retained by the stationary phase while the pure components is easily eluted.

(A) direct combination;

14 (or) IVA Group of elements are called Carbon family.

Ar. In groups as we go down number of shells increases due to the formation of new shell.

Correct option is (a) Debtor

The valency of A is 1 and B is 2.

When two or more elements or compounds which do not react chemically with each other are mixed in any proportion, a mixture is formed. 

Examples: Air, steel, milk.

In a gas intermolecular forces are very weak and the distance between the particles is very large, as a result gas has indefinite volume and shape.

A substance produced by a chemical reaction of two or more elements combined in a fixed proportion is called a compound. 

Examples: Water, common salt, sugar.

1. The proportion of constituent elements in a compound is constant. 

2. The properties of a compound is different than those of the constituent elements.

1. The constituent molecules of mixture are different from each other and notoined by chemical bonds. 

2. The proportion of constituent substances are retained in the mixture. 

3. The constituents of a mixture can be separated by a physical process.

The particles of solid are very close to each other and the distance between them is minimum.

Correct option is (a) mixture

Correct option is (c) maximum

1. All the atoms/molecules of an element are alike. 

2. Atoms/molecules of different elements are different. 

3. An element cannot be decomposed into simple substances by any chemical reaction or simple physical process.

A heterogeneous mixture in which the particles cannot be seen with a naked eye is called a colloid. The diameter of colloidal particles is around 10^-5 m.

1. A solution is clear and transparent, it passes through a filter paper. 

2. The particles are not visible to the naked eye. 

3. A light can easily pass through it without scattering. 

4. A solution is homogeneous mixture.

• Elements: Sodium, nitrogen, mercury. 
• Compounds: Sugar, sodium carbonate, sulphuric acid, potassium dichromate. 
• Mixtures: Air, stainless steel, cement.

1. In suspension, the solute particles do not dissolve but remain suspended in it. The liquid and solid components of suspension are separated by filtration. 

2. The particles are visible to the naked eye. 

3. The particles in suspension are of very small size and scatter a beam of light passing through it. 

4. It is heterogeneous in nature.

Examples of gas in liquid: Chlorinated water, hydrochloric acid.

A type of matter composed of only one kind of substances where each smallest indivisible part of it has the same properties is called an element. It cannot be subdivided into simpler substances by any physical or chemical means. 

Examples: Oxygen, nitrogen, silver.

Mercury (Hg), Bromine (Br₂)

1. In a colloid, the particles are spread uniformly throughout the solution. 

2. The size of the particles is less than that of the particles in a suspension. 

3. The particles are not visible to the naked eye. 

4. The particles scatter a beam of light.

5. A colloidal solution appears to be homogeneous, but actually it is heterogeneous.

(i) Hydrogen (H₂), Oxygen (O₂).

(ii) Iron (Fe), Copper (Cu), Silver (Ag).

(iii) Sea water, blue vitriol dissolved in water

(iv) Milk, blood.