Predicting chemical reactions

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This question is about elements in Group 7 of the Periodic Table.

The table shows some properties of Group 7 elements.

Element	Molecular formula	Melting point ( $∘C^\circ\text{C}$ )	Boiling point ( $∘C^\circ\text{C}$ )	Order of reactivity
Fluorine	$F2\text{F}_2$	$- 220$	$- 188$	most reactive $↓\downarrow$
Chlorine	$Cl2\text{Cl}_2$	$- 101$	....................	$↓\downarrow$
Bromine	$Br2\text{Br}_2$	....................	$59$	$↓\downarrow$
Iodine	$I2\text{I}_2$	$114$	$184$	$↓\downarrow$
Astatine	$At2\text{At}_2$	$302$	$337$	least reactive

Complete the table by estimating the missing boiling point of chlorine and the melting point of bromine. Use ideas about trends down Group 7.

[2]

Chlorine reacts with sodium bromide, $NaBr\text{NaBr}$ , in a displacement reaction. Write the balanced symbol equation for this reaction.

[2]

Explain, in terms of the arrangement of electrons, the decrease in reactivity from fluorine to astatine.

[3]

Sodium reacts with chlorine to form sodium chloride according to the equation:

$2Na+Cl2→2NaCl2\text{Na} + \text{Cl}_2 \rightarrow 2\text{NaCl}$

Calculate the mass of sodium chloride that can be made from $g3.45\text{ g}$ of sodium. Give your answer to 3 significant figures.

(The relative atomic mass, $A_r$ , of $Cl\text{Cl}$ is $35.5$ and of $Na\text{Na}$ is $23.0$ ).

[4]

Predicting chemical reactions Questions