Advertisements
Advertisements
Question
Arrange the following:
LiH, NaH and CsH in order of increasing ionic character.
Advertisements
Solution
The ionic character of a bond is dependent on the electronegativities of the atoms involved. The higher the difference between the electronegativities of atoms, the smaller is the ionic character.
Electronegativity decreases down the group from Lithium to Caesium. Hence, the ionic character of their hydrides will increase (as shown below).
LiH < NaH < CsH
RELATED QUESTIONS
What do you understand by electron-rich compounds of hydrogen? Provide justification with a suitable example.
What characteristics do you expect from an electron-deficient hydride with respect to its structure and chemical reactions?
Do you expect the carbon hydrides of the type (CnH2n + 2) to act as ‘Lewis’ acid or base? Justify your answer.
What do you understand by electron-deficient? Provide justification with a suitable example.
What do you understand by electron-precise? Provide justification with a suitable example.
Name the classes of hydrides to which \[\ce{H2O, B2H6}\] and \[\ce{NaH}\] belong.
What do you understand by the term ‘auto protolysis of water’ ? What is its significance?
Molecular hydrides are classified as electron-deficient, electron precise and electron-rich compounds. Explain each type with two examples.
Hydrogen generally forms covalent compounds. Give reason.
An ionic hydride of an alkali metal has significant covalent character and is almost unreactive towards oxygen and chlorine. This is used in the synthesis of other useful hydrides. Write the formula of this hydride. Write its reaction with \[\ce{Al2Cl6}\].
