No questions found
In the 19th and 20th centuries, experimental results showed scientists that atoms consist of a positive, heavy nucleus which is surrounded by electrons.
Then in the 20th century, theoretical scientists explained how electrons are arranged in orbitals around atoms.
(a) The diagram below represents the energy levels of the orbitals present in atoms of the second period (Li to Ne).
(i) Label the energy levels to indicate the principal quantum number and the type of orbital at each energy level.
(ii) On the axes below, draw a sketch diagram of one of each different type (shape) of orbital that is occupied by the electrons in a second-period element.
Label each type.
(iii) Complete the electronic configurations of nitrogen atoms and oxygen atoms on the energy level diagrams below.
Use arrows to represent electrons.
(b) (i) Use the Data Booklet to state the value of the first ionisation energy of nitrogen and of oxygen.
$N$ ................................ $\text{kJ mol}^{-1}$ $O$ ................................ $\text{kJ mol}^{-1}$
(ii) Explain, with reference to your answer to (a)(iii), the relative values of these two ionisation energies.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
529
555
564
Copper, proton number 29, and argon, proton number 18, are elements which have different physical and chemical properties. In the solid state, each element has the same face-centred cubic crystal structure which is shown below.
The particles present in such a crystal may be atoms, molecules, anions or cations. In the diagram above, the particles present are represented by ⊙.
(a) Which types of particle are present in the copper and argon crystals? In each case, give their formula.
[Table_1]
At room temperature, copper is a solid while argon is a gas.
(b) Explain these observations in terms of the forces present in each solid structure.
..................................................................................................
..................................................................................................
..................................................................................................
..................................................................................................
..................................................................................................
..................................................................................................
Although copper is a relatively unreactive element, when it is heated to a high temperature in an excess of chlorine, copper(II) chloride is formed.
When a mixture of argon and chlorine is heated to a high temperature, no reaction occurs.
(c) (i) How does chlorine behave in its reaction with copper?
..................................................................................................
(ii) Suggest a reason for the lack of a reaction between argon and chlorine.
..................................................................................................
..................................................................................................
The melting points of the noble gases neon to xenon are given below.
[Table_2]
(d) Explain why there is an increase in melting point from neon to xenon.
..................................................................................................
..................................................................................................
..................................................................................................
510
567
564
The table below gives data for some of the oxides of Period 3 elements.
[Table_1]
(a) Complete the table by filling in
(i) the ‘bonding’ row by using only the words ‘ionic’ or ‘covalent’,
(ii) the ‘structure’ row by using only the words ‘simple’ or ‘giant’.
(b) From the table of oxides above, suggest the formula of one oxide that is completely insoluble in water.
......................
(c) Separate samples of \( \text{Na}_2\text{O} \) and \( \text{SO}_2 \) were added to water.
(i) For each oxide, write a balanced equation for its reaction with water and suggest a numerical value for the pH of the resulting solution.
Na\(_2\)O
equation ..........................................................................................
pH .............
SO\(_2\)
equation ..........................................................................................
pH .............
(ii) Construct a balanced equation for the reaction that occurs when a solution of \( \text{Na}_2\text{O} \) in water reacts with a solution of \( \text{SO}_2 \) in water.
.................................................................................................................................................................
(d) Separate samples of the oxides MgO and SiO\(_2\) are melted. Each molten sample is then tested to see whether or not it conducts electricity.
Suggest what would be the results in each case. Explain your answers.
MgO ...................................................................................................................................
.........................................................................................................................................................
SiO\(_2\) ................................................................................................................................
.........................................................................................................................................................
596
592
574
An organic compound, E, has the following composition by mass:
C, 48.7%; H, 8.1%; O, 43.2%.
(a) Calculate the empirical formula of E.
(b) When vaporised in a suitable apparatus, 0.130 g of E occupied a volume of 58.0 cm3 at 127°C and 1.00 × 105 Nm−2.
(i) Use the expression $pV = \frac{mRT}{M_r}$ to calculate $M_r$ of E,
where $m$ is the mass of E.
(ii) Hence calculate the molecular formula of E.
(c) Compound F, is an ester with the molecular formula C4H8O2.
F is one of four isomers, S, T, U, and V, that are all esters.
In the boxes below, the structural formula of S is given.
Draw the structural formulae of the other three isomers of F that are esters.
(d) When the ester F is hydrolysed, an alcohol G is produced.
(i) What reagent can be used to hydrolyse an ester to an alcohol?
(ii) What other type of organic compound is produced at the same time?
(e) On mild oxidation, the alcohol G gives a compound H which forms a silver mirror with Tollens' reagent.
(i) What functional group does the reaction with Tollens' reagent show to be present in compound H? Give the name of this group.
(ii) What type of alcohol is G?
(iii) What could be the structural formula of the alcohol G?
(f) (i) Which of the four isomers, S, T, U, or V, could not be F?
(ii) Explain your answer.
538
574
542
Alkenes such as propene can be readily prepared from alcohols in a school or college laboratory by using the apparatus below. (a) (i) Give the
(ii) Draw the
(iii) What type of reaction occurs in this case? ..........................................................
(b) (i) During the reaction, the material X becomes black in colour. Suggest the identity of the black substance and suggest how it is produced during the reaction. ..................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
(ii) At the end of the experiment, when no more propene is being produced, the delivery tube is removed from the water before the apparatus is allowed to cool. Suggest why this done. ............................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
(iii) The material labelled X can be broken crockery, broken brick or pumice. Give the chemical formula of a compound that is present in one of these materials. ..............................
(iv) State another reagent that could be used to produce propene from an alcohol. ...............................................................
(c) Give the structural formula of the organic product formed when propene reacts separately with
(i) bromine
(ii) cold, dilute manganate(VII) ions
(iii) hot, concentrated manganate(VII) ions
(d) Propene may be polymerised.
(i) What is the essential condition for such a polymerisation? ..........................................................
(ii) The disposal of waste poly(propene) is very difficult. Give one important reason for this.
..........................................................................................................................................
..........................................................................................................................................
583
562
507
