MEDIUM
Earn 100

Give reasons.

 Some elements have variable valencies.

Important Questions on Measurement of Matter

EASY
The numbers of lone pair and bond pairs in hydrazine are, respectively:
EASY
Which of the following compounds can conduct electricity?
MEDIUM
Maximum bond angle at nitrogen is present in which of the following?
MEDIUM
Which of the following compounds contain(s) no covalent bond(s)?

KCl, PH3, O2, B2H6, H2SO4
HARD

Draw the electron dot diagram for the compound given below. Represent the electrons by (.) and (x) in the diagram.

  • Water molecule [Atomic No. of H=1, O=8]
HARD
The lattice energies of NaCl, NaF, KCl and RbCl follow the order
MEDIUM

 Question Image

The above compound represents hydrogen azide, the bond orders of bonds I and II are:

EASY
Which of the following pair contains 2 lone pair of electrons on the central atom?
MEDIUM

Draw the electron dot diagram of Hydronium ion. H=1; O=8

MEDIUM
Write with an example, how according to Lewis concept, a covalent bond is formed.
EASY
Total number of lone pair of electrons in I3- ion is:
HARD
Ethane with the molecular formula C2H6 has
MEDIUM
In ozone molecule, the formal charge on the central oxygen atom is
MEDIUM
Among the following molecules, the one with the largest bond angle at the central atom is
EASY
Arrange the following compounds in increasing order of C-OH bond length: methanol, phenol, p -ethoxyphenol
MEDIUM
The compound having longest C-Cl bond is:
EASY
The number of π -bonds and σ -bonds present in naphthalene are respectively
MEDIUM
The compound(s) with two lone pairs of electrons on the central atom is (are)
MEDIUM
What are covalent compounds? Write any three features and give two examples. 
MEDIUM
Which substance from the following is not obtained during destructive distillation of mineral coal?