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प्रश्न
Why is H2O a liquid and H2S a gas?
उत्तर १
H2O has oxygen as the central atom. Oxygen has smaller size and higher electronegativity as compared to sulphur. Therefore, there is extensive hydrogen bonding in H2O, which is absent in H2S. Molecules of H2S are held together only by weak van der Waal’s forces of attraction.
Hence, H2O exists as a liquid while H2S as a gas.
उत्तर २
Due to high electronegativity of O than S, H2O undergoes extensive intermolecular H-bonding. As a result, H2O exists as an associated molecule in which each O is tetrahedrally suiTOunded by four H2O molecules. Therefore, H2O is a liquid at room temperature.
On the other hand,H2S does not undergo H- bonding. It exists as discrete molecules which are held together by weak van der waals forces of attraction. A small amount of energy is required to break these forces of attraction. Therefore, H2S is a gas at room temperature
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संबंधित प्रश्न
a. Explain the trends in the following properties with reference to group 16:
1 Atomic radii and ionic radii
2 Density
3 ionisation enthalpy
4 Electronegativity
b. In the electolysis of AgNO3 solution 0.7g of Ag is deposited after a certain period of time. Calulate the quantity of electricity required in coulomb. (Molar mass of Ag is 107.9g mol-1)
Account for the following : There is large difference between the melting and boiling points of oxygen and sulphur.
List the important sources of sulphur.
Why does NH3 form hydrogen bond but PH3 does not?
Why are halogens strong oxidising agents?
Explain why inspite of nearly the same electronegativity, oxygen forms hydrogen bonding while chlorine does not.
Arrange the following in the order of property indicated for each set:
F2, Cl2, Br2, I2 - increasing bond dissociation enthalpy.
Give reasons Thermal stability decreases from H2O to H2Te.
Arrange the following in the order of the property indicated against set :
H2O, H2S, H2Se, H2Te − increasing acidic character.
The boiling points of hydrides of group 16 are in the order:
Match the items of Columns I and II and mark the correct option.
| Column I | Column II |
| (A) \[\ce{H2SO4}\] | (1) Highest electron gain enthalpy |
| (B) \[\ce{CCl3NO2}\] | (2) Chalcogen |
| (C) \[\ce{Cl2}\] | (3) Tear gas |
| (D) Sulphur | (4) Storage batteries |
Given below are two statements labelled as Assertion (A) and Reason (R).
Assertion (A): Electron gain enthalpy of oxygen is less than that of Flourine but greater than Nitrogen.
Reason (R): Ionisation enthalpies of the elements follow the order Nitrogen > Oxygen > Fluorine.
Select the most appropriate answer from the options given below:
Write a balanced chemical equation for the reaction showing catalytic oxidation of NH3 by atmospheric oxygen.
Which of the following compound is a peroxide?
______ is a radioactive element in group 16 elements.
______ is a gaseous element of group 16.
