Bonding, Structures Properties and Patterns Homework 1

1. Which type of structure would you expect each of the substances A to D to have?

  1. A grey solid which conducts electricity and melts at 850oC.(1)
  2. A white solid which melts at 770oC and conducts electricity when molten but not in the solid state. (1)
  3. A grey solid which melts at 1410oC and which does not conduct electricity in either solid or molten state. (1)
  4. A white solid which melts at -190oC.(1)

2.Explain the following in terms of particles, structure and bonding.

  1. Ionic substances do not conduct electricity when they are solid but metallic structures do. (1)
  2. Substances with covalent network structures generally do not conduct electricity, except for graphite which is a good conductor.

(1)

3.The structure of ice is very similar to diamond. Explain why a diamond is harder than an ice cube. (1)

4a.Explain why the type of bonding in a compound is related to the positions of its constituent elements in the Periodic Table. (1)

b.Name the type of bonding and the type of structure you would expect for the following compounds.

i) CaCl2ii) PCl3iii) SiCiv) MgOv) C2H6(5)

Total = 13

Bonding, Structures Properties and Patterns Homework 2

Find and correct the errors in the following passage:

Sodium chloride has a high melting point because it has strong intermolecular bonds. These bonds are strong because the chloride ion has a high electronegativity and this leads to a strong attraction for positive sodium.

For an electrical current to flow through a substance it must have charged particles that are free to move. When sodium chloride is melted it will conduct electricity because its electrons are then free to move.

Water is an unusual substance because of hydrogen bonds between separate H2O molecules. These are between the 2- charge on an O atom of one molecule and the 1+ charge on one H atom of another.

This partial charge difference arises because O has lone pairs of electrons and these pull the electrons in each O-H bond towards the O atom. This results in the formation of an induced dipole across each bond.

Diagram showing hydrogen bonding in water:

A constant mass of water requires less energy to boil than it does to melt because the intermolecular bonds are weaker in the liquid state than in the solid. When water boils hydrogen bonds are broken and therefore hydrogen and oxygen are produced.

Liquid water conducts electricity because its electrons are fee to move in this state. Another physical property of water is that it reacts violently with sodium to produce hydrogen gas.

The diamond form of carbon and sodium chloride are both solids with giant structures where the particles are held in fixed within a crystal lattice. Total = 12

Bonding, Structures Properties and Patterns Homework 3

  1. Write the equation for the first ionisation energy of bromine.

(1)

Use the following table to answer questions 2 and 3

Element / Melting Point/oC / Boiling Point/ oC / Conduction when Solid
A / 44 / 280 / No
B / 1083 / 2567 / Yes
C / 1410 / 2355 / No
D / 114 / 184 / No
  1. Which of these elements is most likely to have a covalent network structure and why? (2)
  1. Which of these elements is most likely to have delocalised electrons and why? (2)
  1. Which of the following elements is a solid at room temperature and is made of discrete molecules?

A CarbonB SiliconC SulphurD Boron(1)

  1. The diagram shows the melting points of successive elements across a period in the Periodic Table.

Which of the following is the correct reason for the low melting point of element Y?

A It has weak ionic bonds.

B It has weak covalent bonds.

C It has weakly held outer electrons.

D It has weak forces between molecules.

(1)

  1. Use the following equations to answer the questions a to c:

A / I2(s)  I2(g)
B / I(g)  I+(g) + e-
C / I-(g)  I+(g) + e-
D / I2(g)  2I(g)
E / I-(aq) 1/2 I2(aq) +e-

a. Identify the first ionisation energy of iodine.(1)

b. Identify a change in which covalent bonds are broken.(1)

c. Identify a change in which van der Waals’ forces are broken.(1)

  1. There are various types of structure found among elements. Give the structure for the following:

a. neonb. nitrogenc phosphorousd potassium(4)

  1. a. Why does sulphur have a much lower melting point than silicon?

(1)

b. Suggest a reason for magnesium having a higher melting point than sodium. (1)

  1. In each change name the type of bonding being broken.

a. C(s)  C(g)

b. Ne(l)  Ne(g)

c. Na(l)  Na(g)

d. F2(g)  2F(g)

e. P4(l)  P4(g)(5)

Total = 21

Bonding, Structures Properties and Patterns Homework 4

1. Explain the change in covalent radius of the elements

a) across the Periodic table from lithium to fluorine. (1)

b) down group 1 from lithium to caesium.(1)

2. Explain why a Na+ ion is larger than a Mg2+ ion. (1)

3. Explain a calcium, Ca2+ ion is larger than a Mg2+ ion. (1)

4. a) What is meant by the first ionisation energy of an element? (1)

b)Explain why the ionisation energy is an endothermic process.(1)

c)Write an equation corresponding to the first ionisation energy of Lithium. (1)

d) Explain why the first ionisation energy of fluorine is greater than the first ionisation energy of lithium. (1)

e) Explain why the first ionisation energy of sodium is less than the first ionisationenergy of lithium. (1)

f) Explain why second ionisation energy of sodium is very much higher than the firstionisation energy of sodium. (1)

  1. Using the ionisation energies in the data booklet calculate the energy required for

(1)

6. Explain why a Si4+ ion is smaller than a P3- ion. (1)

Total = 12

Bonding, Structures Properties and Patterns Homework 5

1.

ABCD

metallic monatomiccovalentcovalent

latticenetworkmolecules

Which box, or boxes, shows the bonding in an element that

a) is a non-conductor with a very high melting point?(1)

b) is a non-conductor with a low melting point?(1)

c) is a conductor with a high melting point?(1)

2. The table below shows the elements in the first three periods of the Periodic Table in four classes (A) to (D).

HHe

LiBeBCNOFNe

NaMgAlSiPSClAr

A B C DE

a) Use the key shown above to identify the groups of elements (A,B,C,D or E) which show the following bond types.

i) Monatomic gases.(1)

ii) Covalent networks.(1)

iii) Covalent molecular gases.(1)

iv) Metallic lattice(1)

v) Covalent molecular solids.(1)

b) In which of the groups (A,B,C,D or E) are the following correct

i) mobile electrons allow the element to conduct when solid.(1)

ii) both covalent bonds and van der Waals forces are present?(1)

iii) only covalent bonds are present.(1)

iv) only van der Waals forces are present.(1)

3. Explain why a metal conducts electricity when solid or molten but an

ionic compound conducts only when molten and not when solid.(2)

4. Explain why the melting point increases from top to bottom going down group 7 (the halogens). (1)

5. Two types of carbon are diamond and fullerene.

How does the structure of fullerene differ from that of diamond?(2)

Total = 17

Bonding, Structures Properties and Patterns Homework 6

1. a) Which type of bonding exists in

i) silicon dioxide(1)

ii) sulphur dioxide(1)

b) Use the data booklet to find the boiling points of these two compounds:

silicon dioxide and sulphur dioxide (2)

c) Explain why the boiling points are so different. (1)

2. Copy and complete the table below.

Note:- mention both intermolecular and intramolecular bonding where appropriate.

ElementType of bonding Structure

Sodium lattice or network

Siliconcovalent

Phosphorus

(4)

3. Copy and complete the table below:

Note:- mention both intermolecular and intramolecular bonding where appropriate.

Compound Type of bondingStructure

SiO2

CCl4 covalent intramolecular and

van der Waals forces intermolecular

LiCllattice or network

(4)

4.

ABC

Cl2HFNaCl

DEF

C2H5OH CH3COCH3SiO2

Which box, or boxes, shows a substance

a) with van der Waals attractions only between molecules?(1)

b) with hydrogen bonding between molecules?(1)

c) with polar attractions, but not hydrogen bonding, between molecules? (1)

d) with a network of oppositely charged ions(1)

5.

A B C

covalent bonding polar covalent bonding metallic bonding

D E F

van der Waals forces hydrogen bonding ionic bonding

Which box, or boxes, shows a type of bonding or force of attraction that:-

a) is responsible for the low melting point of noble gases?(1)

b) exists between molecules?(1)

c) could be considered to be intermediate between ionic and covalent bonding? (1)

d) allows electrons a lot of movement?(1)

e) is important when none of the others are present?(1)

Total = 22

Bonding, Structures Properties and Patterns Homework 7

  1. Explain why:

a. The potassium atoms are larger than the sodium atom.(1)

b. The chlorine atom is smaller than the sodium atom.(1)

  1. Can you suggest a reason for the large difference between 1st and 2nd ionisation energies for each of the group 1 elements? (1)
  1. From the table of ionisation levels for the elements in the Data Book:

a. What trend in the first ionisation energies do you observe within the group of halogen elements? (1)

b. Representing a halogen atom by X, write an equation to show what is happening during the first ionisation process. (1)

c. Offer an explanation in terms of atomic structure for the trend observed. (1)

d. Suggest a reason for the lack of ionisation energy data for the element astatine (At, atomic number 85). (1)

  1. The second period of the Periodic Table consists of the elements lithium to neon.

a. List the elements that make up the second period in a table along with melting point and indicate the type of bonding that is being broken when each element melts. (2)

b. The first ionisation energy of oxygen is 1324kJmol-1. Write the equation for this change. (1)

c. Explain the general trend in the first ionisation energies between lithium and neon? (2)

  1. Diamond and graphite are well known forms of the element carbon. New forms of pure carbon have recently been made. They exist as individual molecules of different sizes and are called fullerenes. The main fullerene has the formula C60.

a. How does the structure of a fullerene differ from diamond?(2)

b. Fullerenes were first made by passing a high current of electricity through a graphite rod in an atmosphere of helium. This caused the graphite to vapourise. Suggest why helium was used? (1)

c. Fullerenes can be made into hydrocarbons. One such hydrocarbon has the formula C60H36. Describe a chemical test which could be carried out on a solution of C60H36 to show whether the hydrocarbon is saturated or unsaturated. (1)

Total = 16

Bonding, Structures Properties and Patterns Homework 8

  1. Write the equation for the first ionisation energy of fluorine.(1)
  1. Which equation represents the second ionisation energy of copper?

a. Cu+(g)  Cu2+(g) + e-

b. Cu(g)  Cu2+(g) + 2e-

c. Cu+(s)  Cu2+(s) + 2e-

d. Cu(s)  Cu2+(g) + 2e-

(1)

  1. Explain why potassium has a larger covalent radius than sodium.(1)
  1. What is the energy change required for the following reaction:

Al(g)  Al3+(g) + 3e- (1)

  1. Between 98oC and 883oC sodium exists as a liquid. Which of the following elements exists as a liquid over the greatest temperature range?

a. Magnesiumb. Aluminiumc. Silicond. Phosphorus(1)

  1. What causes the difference in covalent radius of sodium and silicon?(2)
  1. Find and correct the 2 mistakes in the following:

Going down group 7 of the Periodic Table the covalent radius increases and the nuclear charge decreases and the electronegativity increases. (2)

  1. What effect does increasing mass have on van der Waals forces?(1)
  1. Explain why the first ionisation energy of potassium is less than the second ionisation energy of potassium. (1)
  1. a. Why does covalent radius increase going from magnesium to barium?

(1)

b. Why does covalent radius decrease going from magnesium to sulphur?

(1)

Total = 13

Bonding, Structures Properties and Patterns Homework 9

  1. The American scientist Linus Pauling devised a scale to compare the attraction of atoms for bonding electrons. This scale is called the electronegativity scale. Some electronegativity values are shown in the Data Book.

a. Which group of the Periodic Table contains elements with no quoted values for electronegativity? (1)

b. Use the electronegativity values to explain why carbon disulphide contains pure covalent bonds. (1)

c. Explain the trend in the electronegativity values of the group 7 elements. (1)

  1. Calculate the differences in electronegativity for the elements in the following compounds and indicate which compound will be the most ionic and which will be the least ionic:

a. KBrb. NaIc. CsCl(3)

  1. The graph shows the boiling points of the group 6 hydrides:

a. Explain why the boiling points increase from H2S to H2Te.(1)

b. Why does H2O have an unusually high boiling point compared to the other group 6 hydrides? (2)

  1. The first 20 elements of the periodic table can be categorised according to their bonding and structure.

a. Give two examples for each of the following categories:

Monatomic gases

Covalent network solids

Diatomic covalent gases

Discrete covalent molecular solids

Metallic lattice solids(5)

b. Which of the types contains the elements with the greatest attraction for the electrons in a covalent bond? (1)

Total = 15