Chapter 4 - Chemical bonding

Question 1

What is dative/coordinate bonding?

Answer 1

When the two shared electrons come from the same atom

Question 2

What angle and shape does a molecule with two bond pairs make?

Answer 2

180 degrees, and linear

Question 3

What angle and shape does a molecule with three bond pairs make?

Answer 3

120 degrees, and trigonal planar

Question 4

What angle and shape does a molecule with four bond pairs make?

Answer 4

109.5 degrees, and tetrahedral

Question 5

What angle and shape does a molecule with five bond pairs make?

Answer 5

120 and 90 degrees, and trigonal bipyramid

Question 6

What angle and shape does a molecule with six bond pairs make?

Answer 6

90 degrees, octahedral

Question 7

What angle and shape does a molecule with three bond pairs and 1 lone pair make?

Answer 7

107 degrees, and pyramidal

Question 8

What angle and shape does a molecule with two bond pairs and 2 lone pairs make?

Answer 8

104.5 degrees, and bent/angular

Question 9

What is an examples of bent molecules?

Answer 9

water

Question 10

What angle and shape does a molecule with four bond and 2 lone pairs make?

Answer 10

90 degrees, and square planar

Question 11

What is the formula of ammonia

Answer 11

NH3

Question 12

What is the formula of ammonium

Answer 12

NH4

Question 13

What are the three main types of intermolecular forces?

Answer 13

Hydrogen bonds, Van der Waals, permanent dipole-dipole forces

Question 14

What is another name for ionic bonds?

Answer 14

Electrovalent bonds

Question 15

What do bond lengths depend on?

Answer 15

How strong the force of attraction is, which results in a stronger bond

Question 16

What do the shape of bond angles depend on?

Answer 16

The numbers of electron pairs and bond pairs surrounding each atom

Question 17

Which bond occurs when hybridized orbitals overlap linearly?

Answer 17

Sigma bonds

Question 18

Which bond occurs when hybridized orbitals overlap sideways ?

Answer 18

pi bonds

Question 19

Describe the attraction forces between metallic bonding

Answer 19

a regular lattice structure made up of strong electrostatic forces between positive charges and the negative charges of delocalised electrons

Question 20

What are the factors that increase the strength of metallic bonding

Answer 20

increasing positive charge on the ions, decreasing the size of metal ions, increasing numbers of mobile electrons per atom

Question 21

Which are more reactive, dipoles or non-polar molecules?

Answer 21

Dipoles

Question 22

Why can graphite conduct electricity, and graphite cannot?

Answer 22

Graphite has delocalised electrons, while diamond does not

Question 23

What causes the increase of Van der Waals’?

Answer 23

Increased number of electrons (and the protons),

Increasing the number of contact points between molecules (work best will crystalline structures)

Question 24

Which elements are needed to be present for hydrogen bonding to occur?

Answer 24

Fluorine, oxygen or nitrogen, that have an available lone pair

Question 25

What properties did hydrogen bonding give water?

Answer 25

High enthalpy change of evaporation and boiling point, surface tension and viscosity, ice is less dense than water (because of the three-dimensional hydrogen bonded network of water molecules)

Question 26

What are some properties of covalent bonds in room temperature?

Answer 26

they are usually liquid or gas, they have low melting points, low boiling points, and low enthalpy changes of vaporisation. If they are solid in room temperature that means that their Van der Waal forces are very high

Question 27

What interaction occurs when ionic bonds dissolve in water?

Answer 27

ion-dipole interactions