If both adsorption and absorption take place simultaneously, the precess is called..................... .

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sorption

Adsorption of a gas on the surface of solid is generally accompained by decrease in entropy. Still it is a spontaneous process. Explain.

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Adsorption is an exothermic process, i.e., energy factor favours the process. As \(\triangle G=\triangle H-T\triangle S,\) in adsorption, though \(\triangle S\) is-ve but \(\triangle H\) is also-ve and \(\triangle H>T\triangle S\) in magnitude so that is \(\triangle G\) -ve. Hence, the process is spontaneous.

How can we remove moisture from glass apparatus?

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This can be done by placing anhydrous CaCl₂ in the apparatus which absorbs the moisture.

Draw the structure of CIF₃

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Why is the solubility of haloalkanes in water very low?

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It is because haloalkanes are less polar and cannot form H-bonds with water.

Why is there a large difference in the boiling points of butanal and butan-1-ol?

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It is because butanol is associated with intermolecular H-bonding, whereas butanal is not.

Arrange the following in increasing order of their boiling point: C₂H₅NH₂, C₂H₅OH, (CH₃)₃N

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Boiling points depend upon the extent of H-bonding which, in turn, depends upon :

(i) electronegativity of element carrying the H-atoms and (ii) the number of H-atoms on it. Since O is more electronegative than N, therefore, O forms stronger H-bonds than N. In other words, b.p. of C₂H₅OH is higher than those of C₂H₅NH₂ and (CH₃)₃N. Further, C₂H₅NH₂ carries two H-atoms on N but (CH₃)₃ N does not carry any H-atom on N. Therefore, CHNH forms H-bonds but (CH) N does not. In other words, b.p. of CHNH is higher than that of (CH)N. ₂H₅NH₂ forms H-bonds but (CH₃)₃N does not. In other words, b.p. of C₂H₅NH₂ is higher than that of (CH₃)₃N. Thus, the overall b.ps of the three compounds increase in the order : 

(CH₃)₃N < C₂H₅NH₂ < C₂H₅OH

A (C₃H₉N) reacts with benzenesulphonyl chloride to give a solid insoluble in alkali. Give the structure of A.

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Since A (C₃H₉N)₃H₉N) reacts with benzenesulphonyl chloride to give a solid insoluble in alkali, (A) must be a \({ 2 }^{ \circ }\)  amine ; i.e., CH₃-NH-CH₂ CH₃ (ethylmethylamine).

Amino acids behave like salts rather than simple amines or carboxylic acids.Explain.

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Amino acids behave like salts rather than simple amines or carboxylic acids. This behavior is due to the pressure of both acidic and basic groups in the same molecule. In aqueous solution, the carboxyl group can lose a proton, an amino group can accept a proton, giving rise to a dipolar ion known as a zwitter ion.

What is the number of atoms in a unit cell of a simple cubic crystal?

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The number of atoms in a unit cell of a simple cubic crystal is one \(\left[ 8\times \frac { 1 }{ 8 } =1 \right] \).

How is ferromagnetism different from paramagnetism?

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Ferromagnetism is the property due to which a substance remain magnetic field, e.g. Fe, Co,Ni shown ferromagnetism.
Paramagnetism is the property due to which a substance  becomes of unpaired electrons, e.g.most of transition metals shown paramagnetism.

What is meant by point defect in crystals?

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The defect caused by missing or displacement of atoms or ions in a crystal is called point defect.

What happens when blood cells are placed in pure water ?

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Due to osmosis, water molecules move into blood cells through the cell walls. As a result, blood cells swell and may even burst.

Define specific conductivity (specific conductance).

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Specific conductance is defined as conductance of electrolyte when distance between electrodes is 1 cm and area of cross section is 1 cm² .

How is cell constant calculated from conductance values ?

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Cell constant = specific conductance/observed conductance.