[Maximum number: 1]

The symbols of the elements of Period 3 of the Periodic Table are shown.

Answer the following questions about these elements.
Each symbol may be used once, more than once or not at all.
Write the symbol of the element which:

is found in the ore zinc blende. [1]
[Total: 8]

Question 2 starts on the next page.

[Maximum number: 2]

This question is about gases.

The following substances are gases at room temperature.

Identify, by letter:

two gases which exist as diatomic molecules [2]

[Maximum number: 1]

Which compound is silicon(IV) oxide?

melting point
$/^{\circ} \mathrm{C}$

good electrical
conductor when solid

good electrical
conductor when molten

-73

no

801

no

yes

1495

yes

1710

no

[Maximum number: 1]

Which row shows the formulae of sodium carbonate, zinc nitrate and ammonium sulfate?

sodium carbonate

zinc nitrate

ammonium sulfate

$\mathrm{Na}_{2} \mathrm{CO}_{3}$

$\mathrm{ZnNO}_{3}$

$\left(\mathrm{NH}_{4}\right)_{2} \mathrm{SO}_{4}$

$\mathrm{Na}_{2} \mathrm{CO}_{3}$

$\mathrm{Zn}\left(\mathrm{NO}_{3}\right)_{2}$

$\left(\mathrm{NH}_{4}\right)_{2} \mathrm{SO}_{4}$

$\mathrm{NaCO}_{3}$

$\mathrm{ZnNO}_{3}$

$\left(\mathrm{NH}_{3}\right)_{2} \mathrm{SO}_{4}$

$\mathrm{NaCO}_{3}$

$\mathrm{Zn}\left(\mathrm{NO}_{3}\right)_{2}$

$\left(\mathrm{NH}_{3}\right)_{2} \mathrm{SO}_{4}$

[Maximum number: 1]

Caffeine is a stimulant found in coffee.

caffeine

Which formula represents caffeine?

A

$\mathrm{C}_{7} \mathrm{H}_{10} \mathrm{~N}_{4} \mathrm{O}_{2}$

B

$\mathrm{C}_{8} \mathrm{H}_{10} \mathrm{~N}_{3} \mathrm{O}_{2}$

C

$\mathrm{C}_{8} \mathrm{H}_{10} \mathrm{~N}_{4} \mathrm{O}_{2}$

D

$\mathrm{C}_{8} \mathrm{H}_{11} \mathrm{~N}_{4} \mathrm{O}_{2}$

[Maximum number: 1]

Which statements about hydrogen and oxygen are correct?

hydrogen and oxygen
can react to produce
electrical energy

hydrogen and oxygen can
be made by the electrolysis of
dilute aqueous sodium chloride

$\chi$

$\boldsymbol{\chi}$

✓

$\boldsymbol{\chi}$

✓

[Maximum number: 1]

Soluble salts can be made by adding a metal carbonate to a dilute acid.

Give the formula of the dilute acid which reacts with a metal carbonate to form a nitrate salt.

[Maximum number: 1]

The symbol equation for the industrial production of ammonia is shown.

\mathrm{N}_{2}(\mathrm{~g})+3 \mathrm{H}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{NH}_{3}(\mathrm{~g}) \quad \Delta H=-90 \mathrm{~kJ} / \mathrm{mol}

An incomplete symbol equation for the preparation of ammonia in the laboratory is shown.

\mathrm{CaO}+2 \mathrm{NH}_{4} \mathrm{Cl} \rightarrow \mathrm{CaCl}_{2}+\ldots \ldots \ldots \ldots \ldots \ldots \ldots \ldots . .+2 \mathrm{NH}_{3}

Name $\mathrm{NH}_{4} \mathrm{Cl}$ .

[Maximum number: 2]

This question is about phosphorus and compounds of phosphorus.

(a)

A phosphorus molecule contains four phosphorus atoms only.

What is the formula of a phosphorus molecule?

[ 1 ]

(b)

The phosphonium ion, $\mathrm{PH}_{4}{ }^{+}$ , is similar to the ammonium ion.

[ 1 ]

(i)

State the formula of the ammonium ion.

[ 1 ]

[Maximum number: 1]

The Haber process is used to manufacture ammonia.

Ammonia reacts with an acid to form ammonium sulfate, $\left(\mathrm{NH}_{4}\right)_{2} \mathrm{SO}_{4}$ .

State the formula of the acid used.

Question 1(h)

Question 1(a)(ii)

Question 4

Question 7

Question 8

Question 8

Question 2(a)

Question 3(f)(ii)

Question 4

Question 4(a)

Question 4(f)

Question 4(f)(i)

Question 3(c)(i)