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Question
List the important sources of sulphur.
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Solution 1
Sulphur mainly exists in combined form in the earth’s crust primarily as sulphates [gypsum (CaSO4.2H2O), Epsom salt (MgSO4.7H2O), baryte (BaSO4)] and sulphides [(galena (PbS), zinc blends (ZnS), copper pyrites (CuFeS2)].
Solution 2
Sulphur mainly occurs in the combined states in earth’s crust in the form of sulphates and sulphides.
Sulphates : gypsum (CaSO4.2H2O); epsom (MgSO4.7H2O); baryte (BaSO4), etc.
Sulphides : Galena (PbS); zinc blende (ZnS); copper pyrites (CuFeS2); iron pyrites (FeS2), etc. Traces of sulphur occur’as H2S and in organic materials such as eggs, proteins, garlic, onion, mustard, hair and wool.
RELATED QUESTIONS
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)
Give reasons: SO2 is reducing while TeO2 is an oxidising agent.
Account for the following : There is large difference between the melting and boiling points of oxygen and sulphur.
Give reasons for the following : Oxygen has less electron gain enthalpy with negative sign than sulphur.
Why does NH3 form hydrogen bond but PH3 does not?
Knowing the electron gain enthalpy values for \[\ce{O -> O-}\] and \[\ce{O -> O^{2-}}\] as −141 and 702 kJ mol−1 respectively, how can you account for the formation of a large number of oxides having O2− species and not O−?
(Hint: Consider lattice energy factor in the formation of compounds).
Arrange the following in the order of the property indicated against set :
H2O, H2S, H2Se, H2Te − increasing acidic character.
Give reactions for the following:
O – O single bond is weaker than S – S single bond.
Arrange the following in order of the property indicated set.
HF, HCl, HBr, HI - decreasing bond enthalpy.
Which of the following statement is incorrect?
Which of the following statements are correct?
(i) \[\ce{CaF2 + H2SO4 -> CaSO4 + 2HF}\]
(ii) \[\ce{2HI + H2SO4 -> I2 + SO2 + 2H2O}\]
(iii) \[\ce{Cu + 2H2SO4 -> CuSO4 + SO2 + 2H2O}\]
(iv) \[\ce{Nacl + H2SO4 -> NaHSO4 + HCl}\]
Write a balanced chemical equation for the reaction showing catalytic oxidation of NH3 by atmospheric oxygen.
Out of \[\ce{H2O}\] and \[\ce{H2S}\], which one has higher bond angle and why?
The correct order of ΔiHs among the following elements is
Which of the following compound is a peroxide?
What is the basicity of \[\ce{H3PO4}\]?
Given below are two statements:
Statement I: The boiling point of hydrides of Group 16 elements follows the order:
H2O > H2Te > H2Se > H2S
Statement II: On the basis of molecular mass, H2O is expected to have a lower boiling point than the other members of the group but due to the presence of extensive H-bonding in H2O, it has a higher boiling point.
In the light of the above statements, choose the correct answer from the options given below:
