ES.6 Flashcards
Atom economy and hydrogen halides
What is atom economy?
The percentage of reactant atoms that end up as the desired product.
What is the relationship between atom economy and waste?
the higher the atom economy, the less the waste.
What is the equation for atom economy?
Atom economy = molecular mass of desired product / molecular mass of reactants.
When HCl is produced alongside the desired product is it considered a co product or a by product?
Co product because it is useful and can be used in other reactions.
What is the trend in difficulty for halides to lose electrons and return to their atom states?
As you go down the group this becomes easier, halides are better reducing agent as you go down the group.
Is it a redox reaction when HCl or HF are formed as gas when NaCl or NaF react with concentrated sulfuric acid?
No, the oxidation numbers are not change.
What is the appearance of HCl gas?
White fumes.
When reacting NaBr with concentrated sulfuric acid, as well as some HBr gas formed, what other products would there be from side reactions?
Sulfur dioxide may be formed, as bromide ions produced are strong enough reducing agent to be able to reduce the sulfuric acid to sulfur dioxide. Also some bromine vapor and water would be formed.
When reacting NaI with concentrated sulfuric acid, as well as some HI gas formed, what other products would there be from side reactions?
Hydrogen sulfide gas may be formed, as iodide ions produced are even stronger reducing agents, and they are able to reduce the sulfuric acid even further to hydrogen sulfide gas. Also some iodine and water would be formed.
What acid is used instead of sulfuric acid to produce pure HBr and HI gases?
Concentrated phosphoric acid.
What is the trend in thermal stability for hydrogen halides?
As you go down the group, hydrogen halides’ thermal stabilities decrease. This is because bond strength between the hydrogen and the halide decrease and less energy is needed to break the bond as you go down the group.
What solution is formed when hydrogen halides dissolve in water?
They dissociate to form strong acids. Apart from HF.
What is formed when hydrogen halides react with ammonia?
Salts of ammonium halide. This can be seen as a white cloud forming during an experiment.
