Covalent bonding

Question 1

What is a covalent bond?

Answer 1

Strong electrostatic attraction between a shared pair of electrons and the nuclei of bonded atoms.

Question 2

who does it occur between?

Answer 2

between 2 non metals

Question 3

What is used to represent covalent bonds?

Answer 3

Dot-cross diagrams

Question 4

What happens in a covalent bond?

Answer 4

electrons are SHARED between the atoms and atoms obtain a FULL OUTER SHELL of electrons

Question 5

Which type of bond includes sharing only one pair of electrons

Answer 5

Single covalent bond

Question 6

what type of covalent bonding is H20

Answer 6

single covalent

Question 7

What is the type of bonding when more than 1 pair of electrons is shared

Answer 7

multiple covalent bonding

Question 8

Which type of bond includes sharing only TWO PAIRS of electrons

Answer 8

double bond

Question 9

Which type of bond includes sharing only 3 pairs of electrons

Answer 9

triple bond

Question 10

What is dative covalent bonding

Answer 10

One atom donates both of the electrons in a covalent bond (i.e donates a lone pair)

Question 11

example of a molecule where there is dative covalent bonding?

Answer 11

NH4+ (AMMONIUM)

Question 12

why is the ammonium positive overall?

Answer 12

The hydrogen lost an electron an d received a lone pair from nitrogen in a dative covalent bond

Question 13

What is another name for dative covalent bonds

Answer 13

co-ordinate bonds

Question 14

example of a molecule where there is triple covalent bonding

Answer 14

N2 (Nitrogen gas)

Question 15

What are substances made of simple molecules

Answer 15

simple molecular substances

Question 16

what forces are between each MOLECULE in the simple substance

Answer 16

weak intermolecular forces

Question 17

Do simple molecular substances have low or high melting and boiling point?

Answer 17

low due to weak intermolecular forces

Question 18

why do simple molecular substances have low b.p and m.p?

Answer 18

WEAK intermolecular forces
between THE MOLECULES
so LOW AMOUNT OF ENERGY needed to DISRUPT these intermolecular forces

Question 19

simple molecular substances are SOLUBLE in non polar solvents true or false

Answer 19

TRUE

Question 20

can simple molecular substances conduct electricity ?
Why?

Answer 20

No, since there are no electrons or particles that can move freely and carry charge

Question 21

Example of giant covalent substance

Answer 21

SiO2 (silicon dioxide)

Question 22

giant covalent substances have high melting and boiling point. (TRUE OR FALSE)

Answer 22

True

Question 23

why do giant covalent substances have high melting and boiling point?

Answer 23

-Strong covalent bond existing throughout the lattice
-Lots of energy is required to break these bonds between atoms therefore high melting and boiling point

Question 24

Are giant covalent substances soluble in polar or non-polar solvents?

Answer 24

No, they are insoluble in either of the two.

Question 25

WHY Are giant covalent substances insoluble in polar and non-polar solvents?

Answer 25

Strong covalent bonds are not disrupted by any of the solvents

Question 26

can giant covalent substances conduct electricity? is there an exception?

Answer 26

No, they cannot due to absence of freely moving particles which can carry charge. But graphite is an exception and has delocalised electrons between the layers of lattice

Question 27

What happens when electrons are applied to graphite

Answer 27

electrons move freely parallel to graphite layers and conduct electricity

Question 28

Do covalent compounds have molecular LATTICE or exist as molecules in SOLID STATE?

Answer 28

LATTICE STRUCTURE