Bonding

Question 1

What are ionic compounds made up of?

Answer 1

Metal and non-metal

Question 2

What are covalent compounds made up of?

Answer 2

non-metals

Question 3

Is ammonium nitrate ionic or covalent?

Answer 3

ionic overall, but has covalent bonding in each part.

Question 4

What are ions? When are they formed?

Answer 4

charged particles which are formed when atoms lose or gain electrons

Question 5

Draw a dot and cross diagram showing the formation of an ion by magnesium

Answer 5

See page 2

Question 6

What does isoelectronic mean?

Answer 6

same number of electrons

Question 7

Write the electron configuration of Ga³⁺

Answer 7

1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ (4s electrons removed before 3d)

Question 8

What is the charge of: hydroxide; hydrogencarbonate; carbonate; sulfate; phosphate; silver; ammonium; zinc; copper; iron

Answer 8

OH⁻
HCO₃⁻
SO₄²⁻
PO₄³⁻
NH₄⁺
Zn⁺²
Cu⁺²
Fe⁺²/ Fe⁺³⁺

Question 9

What is ionic bonding?

Answer 9

electrostatic attraction between oppositely charged ions – has a three-dimensional giant lattice structure

Question 10

What do ionic compounds have high melting and boiling points?

Answer 10

SEFABOCI – require a lot of energy to break

Question 11

Why do ionic compounds have low volatility?

Answer 11

SEFABOCI – do not evaporate easily

Question 12

Why are ionic compounds hard?

Answer 12

SEFABOCI

Question 13

Why don’t ionic compounds conduct electricity when solid? When do they conduct electricity? Why?

Answer 13

ions are not free to move – held tightly in place by (giant) lattice structure

When molten or dissolved in water – ions become free to move

Question 14

Why are ionic compounds often soluble in water?

Answer 14

Water is polar. Ion-dipole interactions between ions & polar water molecules releases enough energy to overcome electrostatic forces between ions.

Question 15

Why are ionic compounds usually insoluble in non-polar solvents/organic solvents?

Answer 15

interactions between solvent molecules and ions are weak – don’t release enough energy to break apart the lattice.

Question 16

What can be used as a measure of the strength of ionic bonding? What type of ions have a high one?

Answer 16

lattice enthalpy – higher, stronger bonding

high charge and small radius

Question 17

What is a lone pair?

Answer 17

a pair of electrons in the outer shell of an atom which is not involved in covalent bonding

Question 18

What is a covalent bond?

Answer 18

electrostatic attraction between positively charged nuclei of both atoms and the shared pair of electrons

Question 19

What is a covalent bond in terms of orbitals?

Answer 19

two atomic orbitals overlap so that the electrons are paired up in a molecular orbital

see page 8 for diagrams

Question 20

What is a coordination bond?

Answer 20

both electrons come from the same atom

Question 21

How to find formal charge?

Answer 21

(number of valence electrons in uncombined atom) - 1/2 (number of bonding electrons) - (number of non-bonding electrons)

Question 22

What is the preferred Lewis formula?

Answer 22

FC closest to 0

Question 23

What is the shape of a molecule and the bond angle with 2 electron domains? Draw it

Answer 23

linear
180°
See page 13

Question 24

What is the shape of a molecule and the bond angle with 3 electron domains? Draw it

Answer 24

Trigonal Planar
120°
See page 13

Question 25

What is the shape of a molecule and the bond angle with 4 electron domains? Draw it

Answer 25

Tetrahedral
109.5°
See page 13

Question 26

What is the shape of a molecule and the bond angle with 5 electron domains? Draw it

Answer 26

trigonal bipyramidal
90° & 120°
See page 13

Question 27

What is the shape of a molecule and the bond angle with 6 electron domains? Draw it

Answer 27

Octahedral
90°
See page 13

Question 28

What is the actual shape of 2 bonding pairs and 1 lone pair; 3, 1; 2, 2; 4, 1; 3, 2; 2, 3; 5, 1; 4, 2

Answer 28

bent
trigonal pyramidal
bent
see-saw
t-shaped
linear
square pyramidal
square planar