11.6 Making salts Flashcards
How to make salts
you can make salts by reacting acids with metal or insoluble bases or soluble bases or carbonates
How to make a zinc sulfate
add the zinc to the sulfuric acid in the beaker and it starts to dissolve and hydrogen bubbles off when bubbling stops when all the acids are used up, remove the excess zinc by filtering this leaves an aqueous solution of zinc sulfate
how to make a salt with an insoluble base like copper oxide
Add some dilute hydrochloric acid to a beaker.
Add powdered insoluble reactant to some acid in a beaker, one spatula at a time, stirring to mix. The mixture will effervesce. Continue adding powder until some unreacted powder is left over - it is in
excess. Filter the mixture in the beaker to remove the excess powder. Allow the water in the solution to evaporate (by heating and/or leaving for a few days) to obtain pure dry crystals of the salt.
CuO + H2So4 —> CuSo4
how to make salt starting with soluble base
it is dangerous to add sodium to acid so to make sodium salt so start with sodium hydroxide both reactants are soluble and gas bubbles of, so how
what is titration
in titration, one reactant is slowly added to another and the presence of an indicator the indicator changes color when the reaction is complete and know when the reaction is compltede in this method you can mix the amounts
what is the steps making sodium chloride
1.) put 25 cubic cm of sodium hydroxide into a flash using a pipette and then add two drops phenolphthalein solution becomes pink
2.) add the acids from a burette, just a little at a time. Swirl the flash carefully, to help the acid and Akali mix.
3.)the indicator suddenly turns colorless. So the alkali has all been used up. the solution is now neutral. Add no more acid!
4.) find how much acid you added from the burette. this tells you how much acid is needed to neutralize 25 cm cubed of the alkali.
5.) now repeat without indicator. put 25cm3 of alkali in the flash add the correct amount of acid to neutralize it.
6.)Finally, heat the solution from the flash to evaporate the water. White crystals of sodium chloride will be left behind.
you would not make lead salts by reacting lead with acids why?
Lead is below hydrogen in the reactivity series, so it cannot displace hydrogen from an acid to form a salt. copper and silver and gold will not react with acid.
