Analysis shows that FeO has a non-stoichiometric composition with

Subject

Chemistry

Class

CBSE Class 12

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 Multiple Choice QuestionsShort Answer Type

1.

CO(g) and H2 (g) react to give different products in the presence of different catalysts. Which ability of the catalyst is shown by these reactions?


2.

Write the coordination number and oxidation state of Platinum in the complex [Pt(en)2Cl2].


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3.

Analysis shows that FeO has a non-stoichiometric composition with formula Fe0.95O. Give reason.


The non-stoichiometry reflect the ease of oxidation of Fe2+ to Fe3+ effectively replacing a small portion of Fe2+ with two thirds their number of Fe3+. Thus for every three "missing" Fe2+ ions, the crystal contains two Fe3+ ions to balance the charge.   i.e. 3Fe2+ = 2Fe3+ to maintain electrical neutrality.


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4.

Complete and balance the following chemical equations :

Fe2+ + MnO4- + H+   


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5.

Complete and balance the following chemical equation:

MnO4- + H2O + I-   


6.

For the reaction,2N2O5 (g)   4 NO2 (g)  + O2 (g) the rate of formation of NO2 (g)  is 2.8 x 10-3 Ms-1. Calculate the rate of disappearance of N2O5 (g).


7.

Among the hydrides of Group-15 elements, which have the

  1. Lowest boiling point?
  2. Maximum basic character?
  3. Highest bond angle?
  4. Maximum reducing character?


8.

Calculate the freezing point of a solution containing 60 g of glucose (Molar mass = 180 g mol–1) in 250 g of water.
(Kf of water = 1.86 K kg mol–1)


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9.

An element ‘X’ (At. mass = 40 g mol–1) having f.c.c. the structure has a unit cell edge length of 400 pm. Calculate the density of ‘X’ and the number of unit cells in 4 g of ‘X’. (NA = 6.022 × 1023 mol–1 )


10.

Give reasons for the following :

Measurement of osmotic pressure method is preferred for the determination of molar masses of macromolecules such as proteins and polymers.


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