10.3- REACTIONS OF HALIDE IONS Flashcards
Can halide ions act as rerducing agents?
yes
What happens in reaction where the halide ion is a reducing agent?
halide ions lose electrons and become halogen molecules
What is the trend in reducing ability linked to?
linked to size of ions
If the ion is larger, how does this affect how easily it loses an electron?
larger the ion, more easily it loses an electron
Why can larger ions lose an electron more easily?
because electron lost from outer shell which is further from nucleus as ion gets larger so attraction to outer electron less
How does reducing power changes down the halogen group?
reducing power increases
What reaction reflects the reducing power of the halide ions?
solid sodium halides react with concentrated sulphuric acid- products different + reflect reducing power of halide ions
What happens when drops of concentrated sulphuric acid is added to solid sodium chloride?
steamy fumes of hydrogen chloride is seen
What is the solid product formed when sodium chloride and concentrated sulphuric acid react?
sodium hydrogensulfate
What is the symbol equation for the reation between sodium chloride and concentrated sulphuric acid?
NaCl (s) + H2SO4 (l) = NaHSO4 (s) + HCl (g)
When sodium chloride and concentrated sulphuric acid react, is this a redox reaction?
it is not a redox reaction
When sodium chloride and concentrated sulphuric acid react, why is it not a redox reaction?
no oxidation state has changed
Why does no oxidation state change?
chlorine is too weak a reducing agent to reduce sulphur in sulphuric acid
What type of reactions is it when sodium chloride and concentrated sulphuric acid react?
acid-base reaction
What can the sodium chloride and concentrated sulphuric acid reaction be used to prepare?
hydrogen chloride gas
What was hydrogen chloride gas once called?
salt gas
Where does a similar reaction to sodium chloride and concentrated sulphuric acid happen?
with sodium fluoride and concentrated sulphuric acid
What dangerous product is formed when sodium fluoride and concentrated sulphuric acid react?
extremely dangerous gas that will etch glass
Is the fluoride ion a weaker or stronger reducing agent in comparison to the chloride ion?
fluoride ion is an even weaker reducing agent than the chloride ion
What happens when sodium bromide and concentrated sulphuric acid react? (2)
steamy fumes of hydrogen bromide and brown fumes of bromine
What else is formed when sodium bromide and concentrated sulphuric acid react?
colourless sulphur dioxide also formed
How many reactions occur when sodium bromide and concentrated sulphuric acid react?
two reactions occur
What is first produced when sodium bromide and concentrated sulphuric acid react?
sodium hydrogensulfate and hydrogen bromide
What type of reactions is it when sodium hydrogensulfate and hydrogen bromide is produced?
acid-base reaction
What is the equation for when sodium hydrogensulfate and hydrogen bromide is produced from reacting sodium bromide and concentrated sulphuric acid?
NaBr (s) + H2SO4 (l) = NaHSO4 (s) + HBr (g)
Why do the bromide ions reduce the sulphuric acid to sulphur oxide?
they are strong enough reducing agents
What is the second reaction of sodium bromide and concentrates sulphuric acid known as?
redox reaction
Are the reactions exothermic or endothermic?
exothermic and some of the bromine vaporises
What do you see when sodium iodide and concentrates sulphuric acid react? (2)
steamy fumes of hydrogen iodide
black solid of iodine
What can be smelt when sodium iodide and concentrates sulphuric acid react?
bad egg smell of hydrogen sulphide gas present
What may also be seen when sodium iodide and concentrated sulphuric acid react?
yellow solid sulphur may also be seen
What is also evolved when sodium iodide and concentrated sulphuric acid react?
colourless sulphur dioxide
How many reactions take place when sodium iodide and concentrated sulphuric acid react?
several reactions occur
What is produced in the acid-base reactions first when sodium iodide and concentrates sulphuric acid react?
hydrogen iodide
What is the equation for when hydrogen iodide is formed when sodium iodide and concentrated sulphuric acid react?
NaI (s) +H2SO4 (l) = NaHSO4 (s) + HI (s)
Is iodide ions or bromide ions better reducing agents?
iodide ions are better reducing agents
As iodide ions are better reducing agents than bromide ions what do they do to sulphuric acid?
reduce sulphur in sulphuric acid even further
As the sulphur in the sulphuric acid is reduced even further by the iodide ions, what does this produce?
sulphur dioxide, sulphur and hydrogen sulphide gas produced
