Unit 1 Revision questions and answers

Page 1

The idea of these questions is to highlight areas that you need to revise the most. Use them however you wish. I used the specification to make the questions so most of Unit 1 is covered here. The website doesn't like subscripts and superscripts unfortunately, I apologise for that. Answers on the next page!

1.

Define the term mass number of an atom.

2.

State the number of each type of fundamental

particle present in a fluoride ion, F-.

3.

Describe how ions in a mass spectrometer reach

the detector.

4.

What two things does the detector measure when

ions reach it?

5.

Give the electron configuration, in terms of s,

p and d subshells, of chromium.

6.

Define the term ionisation energy.

7.

Give three factors which affect ionisation

energy.

8.

Define the term relative atomic mass.

9.

Define the term relative molecular mass.

10.

State the ideal gas equation.

11.

Define the term empirical formula.

12.

Define the term molecular formula.

13.

Give an equation for atom economy.

14.

What is meant by a dative covalent (coordinate)

bond?

15.

Why do the melting and boiling points of metals

increase across a period?

16.

Why do the melting and boiling points of metals

decrease down a group?

17.

Define the term electronegativity.

18.

What can be said about the polarity of a

covalent bond between atoms with a large difference in electronegativity?

19.

What is the strongest type of intermolecular

force, and when does it occur?

20.

When do you get permanent dipole-dipole forces?

21.

What are van der Waals’ forces?

22.

Describe the crystal structure of graphite.

23.

Why does graphite conduct

electricity?

24.

What is the general trend in first ionisation

energy across Period 3 (Na-Ar)?

25.

Which two elements deviate from this trend and

why?

26.

Name the alkane with structural formula CH3CH(CH3)CH(CH3)CH3.

27.

Give the name and displayed formula of a

chain-branching isomerism of the alkane above.

28.

By what process are alkanes separated from crude

oil?

29.

State the meaning of a saturated hydrocarbon.

30.

What are the conditions and the main types of

products of thermal cracking?

31.

What are the conditions and the main types of

products of catalytic cracking?

32.

Give an equation for the removal of NO from

exhaust engines.

33.

Identify a reagent used to remove industrial

sulphur dioxide emissions and explain why it is used.

34.

Draw and name the shape of a molecule of ClF4-,

showing any lone pairs which influence the shape.

35.

What is the bond angle in water?

See how you did, and use this proactively to focus your revision on areas you struggled on. Ask if you're not sure about any of the answers or if I've made a mistake.

Unit 1 Answers

1.

Number of protons + number of neutrons

2.

9 protons, 10 electrons, 10 neutrons

3.

Accelerated by a negative plate; deflected by a

magnetic field (greater m/z ratio = lower deflection)

4.

M/z ratio of ions; relative abundance/size of

current generated

5.

1s22s22p63s23p63d54s1

– remember it deviates from the trend as a half-full d subshell is more stable

than 3d44s2. Can also be written as 4s13d5

6.

The energy required to remove one electron from

each atom of a mole of gaseous atoms of an element (to produce a mole of ions

with a +1 charge)

7.

Atomic radius (distance of outer electrons from

nucleus), nuclear charge and electron shielding

8.

Average mass of one atom of an element x12

Mass of one atom of carbon-12

9.

Average mass of one molecule of a species x12

Mass of one atom of carbon-12

10.

pV=nRT (p=pressure in Pa; V=volume in m3;

n=moles; R=8.31kJmol-1 (given in question); T=temperature in Kelvin

11.

The simplest ratio of the number of atoms of

each element in a compound

12.

The number of atoms of each element in a molecule

13.

Mass of useful products x100%

Total mass of products (or reactants)

14.

A shared pair of electrons where both electrons

originate from/are donated by the same atom

15.

More delocalised electrons/bigger nuclear

charge/smaller atomic radius; stronger electrostatic attraction between

electrons and nuclei/positive ions; stronger metallic bonding.

16.

Outer electrons further from nucleus/more

electron shielding; electrostatic attraction between electrons and nuclei is

weaker, so weaker metallic bonding

17.

The power of an atom to withdraw electron

density from a covalent bond

18.

Very polar

19.

Hydrogen bonds; when hydrogen is bonded to F, O

or N

20.

When you have a polar bond between atoms with a

large difference in electronegativity, i.e. between an atom with a partial

positive charge and one with a partial negative charge

21.

Temporary forces caused by an instantaneous

dipole in one atom which induces a dipole in a second atom of another molecule,

resulting in a slight electrostatic attraction. The weakest type of

intermolecular force

22.

Giant covalent; carbon atoms arranged in

hexagonal layers

23.

Carbon atoms have delocalised electrons which

can carry charge

24.

Increases

25.

Aluminium (outer electron in p subshell –

further from nucleus than s subshell so weaker electrostatic attraction of electron

to nucleus); sulphur (paired electrons in 3p orbital repel)

26.

2,3-dimethylbutane

27.

Name and displayed formula of: hexane;

2-methylpentane; 3-methylpentane; 2,2-dimethylbutane; ethylbutane (any one)

28.

Fractional distillation

29.

Molecule containing only the elements carbon and

hydrogen (hydrocarbon); with only single covalent bonds (saturated)

30.

500-900 degrees C; 70atm; short-chain alkanes

and alkenes

31.

450 degrees C; 10atm; zeolite catalyst; motor

fuels and aromatic hydrocarbons

32.

2NO + 2CO => N2 + 2CO2

33.

Calcium oxide – it is basic so it neutralises

the gas

34.

Square planar (all bond angles 90o);

two lone pairs on the chlorine.

35.

104.5o

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