MEDIUM
Earn 100

Give reasons.

 Some elements have variable valencies.

Important Questions on Measurement of Matter

HARD
Science>Chemistry>Measurement of Matter>Molecular mass and the concept of mole
The lattice energies of NaCl, NaF, KCl and RbCl follow the order
MEDIUM
Science>Chemistry>Measurement of Matter>Molecular mass and the concept of mole
Maximum bond angle at nitrogen is present in which of the following?
MEDIUM
Science>Chemistry>Measurement of Matter>Molecular mass and the concept of mole
Among the following molecules, the one with the largest bond angle at the central atom is
EASY
Science>Chemistry>Measurement of Matter>Molecular mass and the concept of mole
What do you understand by a lone pair of electrons?
MEDIUM
Science>Chemistry>Measurement of Matter>Molecular mass and the concept of mole
Which substance from the following is not obtained during destructive distillation of mineral coal?
EASY
Science>Chemistry>Measurement of Matter>Molecular mass and the concept of mole
Total number of lone pair of electrons in I3- ion is:
EASY
Science>Chemistry>Measurement of Matter>Molecular mass and the concept of mole
The numbers of lone pair and bond pairs in hydrazine are, respectively:
MEDIUM
Science>Chemistry>Measurement of Matter>Molecular mass and the concept of mole
The compound having longest C-Cl bond is:
MEDIUM
Science>Chemistry>Measurement of Matter>Molecular mass and the concept of mole
Write with an example, how according to Lewis concept, a covalent bond is formed.
HARD
Science>Chemistry>Measurement of Matter>Molecular mass and the concept of mole
Ethane with the molecular formula C2H6 has
MEDIUM
Science>Chemistry>Measurement of Matter>Molecular mass and the concept of mole

Give a reason for the following:

Ionic compounds have a high melting point.

HARD
Science>Chemistry>Measurement of Matter>Molecular mass and the concept of mole

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]
MEDIUM
Science>Chemistry>Measurement of Matter>Molecular mass and the concept of mole
In ozone molecule, the formal charge on the central oxygen atom is
MEDIUM
Science>Chemistry>Measurement of Matter>Molecular mass and the concept of mole
Which of the following compounds contain(s) no covalent bond(s)?

KCl, PH3, O2, B2H6, H2SO4
EASY
Science>Chemistry>Measurement of Matter>Molecular mass and the concept of mole
Arrange the following compounds in increasing order of C-OH bond length: methanol, phenol, p -ethoxyphenol
EASY
Science>Chemistry>Measurement of Matter>Molecular mass and the concept of mole
Which of the following pair contains 2 lone pair of electrons on the central atom?
EASY
Science>Chemistry>Measurement of Matter>Molecular mass and the concept of mole
The number of π -bonds and σ -bonds present in naphthalene are respectively
MEDIUM
Science>Chemistry>Measurement of Matter>Molecular mass and the concept of mole
The compound(s) with two lone pairs of electrons on the central atom is (are)
MEDIUM
Science>Chemistry>Measurement of Matter>Molecular mass and the concept of mole

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

MEDIUM
Science>Chemistry>Measurement of Matter>Molecular mass and the concept of mole
What are covalent compounds? Write any three features and give two examples.