Category: chemistry

Give reason for why the enthalpy in case of chemisorption is usually higher than that of physisorption ?

In case of chemisorption there is a partial bond like interaction between the adsorbate and adsorbent . During such an interaction the higher amount of energy is required because bond formation and breaking will require more energy. but on the other hand in case of physisorption the adsorbate and adsorbent particles are simply held together

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Give an example of each , differentiate between multimolecular and macromolecular colloids ?

Multimolecular colloids :- These kind of colloids are formed when many small molecules or atoms are forced to aggregate in the dispersion medium. Thses colliods are lyophobic (solvent hating) in nature. for example gold solution Macromolecular colloids :- These are colloids which are formed of such a molecules which are enough large to have colloidal

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Why is freezing point depression of 0.1 M sodium chloride solution is nearly twice that of 0.1 M glucose solution ?

the depression in freezing point (which is a colligative property) depends upon the number of solute particles present in the solution. when sodium chloride is mixed in the water it dissociates into Na+ and Cl– ions thus this increases the number of particles . but glucose don’t dissociate and its freezing point is higher than

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A 0.1539 molal aqueous solution of cane sugar (molar mass = 342g )  has a freezing point of 271K while the freezing point of pure water is 273.15K . what will be the freezing point of an aqueous solution containing 5g of glucose (molar mass= 180g) per 100 g of solution?

Molality of the given solution = 0.1539m ∆Tf = 273.15 – 271 = 2.15 K Therefore ∆Tf  = Kf .m Kf = ∆Tf / m Kf = 2.15/0.1539  Now mass of the solute W2 = 5g Molar mass of the solute M2 = 180g Mass of the solution W1 = 100g  Now the mass of

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An antifreeze solution is prepared from 222.6 g of ethylene glycol C2H4(OH)2 and 200g of water . Calculate the molality of the solution . If the density of the solution is 1.072 g per / ml -1 , then what shall be the molarity of the solution ?

Solution:- Mass of ethylene glycol (solute) = 222.6 g Molar mass of ethylene glycol ( C2H4(OH)2 = 62g Number of moles of the solute = 222.6 / 62  = 3.59 moles Mass of the solvent (water) in solution = 200g = 0.200Kg Volume of the solution = 422.6 / 1.072 = 394.2 ml                                                 =

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Which of the 3-d series of the transition metals exhibit the largest number of oxidation states and why ?

In case of transition metals the Manganese exhibit large range of oxidation state from +2 to +7. This is due to the fact that it has the highest number of unpaired electrons in its outer shell. The configuration of Mn is [Ar] 3d5 4s2 thius it can use its 7 electrons to show the large

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Give an example each of miscible liquid pairs showing positive and negative deviations from Raoult’s law. Give reasons for each such deviation.

Solution The mixtures showing positive and negative deviations are as follows:- Mixtures showing positive deviation is mixture of ethanol and acetone. The reason behind this is :- in this case the solute and solvent interactions are weaker than the solute-solute and solvent-solvent interactions. Mixtures showing negative deviation is mixture of chloroform and acetone. The reason

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