chpt 8 salts Flashcards
1
Q
What are the methods to prepare salts ?
A
- adding excess solid reactant (reactive metal, base, carbonate)
- titration
- precipitation
2
Q
Describe process and conditions for adding excess to. be used.
A
- prep most soluble salts EXCEPT group 1 and ammonium salts
- excess reactive metal, carbonate and base
- add excess____ into acid (sulfuric acid) and stir
- filter mixture to filter out excess as residue
- heat to saturation
- cool for crystals to form
- wash with little cold distilled water
- dry btwn 2 pieces of filter paper
3
Q
Describe process and conditions for titration.
A
- prep soluble grp 1 and ammonium salts (what adding excess does not prep)
- acid plus soluble base / carbonate
- pipette aqueous sodium hydroxide into conical flask
- add 2 drops of methyl orange (universal indicator)
- add dilute nitric acid from burette, slowly with stirring, until indicator changes colour
- record amt of dilute nitric acid used
- heat to saturation, filter for crystals, wash and dry
4
Q
Describe process and conditions for precipitation.
A
- prep insoluble salts (precipitate, its in the name)
- to reactants used must be in aq form
- aq solution + aq solution -> insoluble salt + aq solution
- mix fixed volume of barium nitrate with excess sodium sulfate together and stir
- insoluble barium sulfate formed as insoluble salt, sodium nitrate as aq solution
- filter to obtain precipitate as residue, wash and dry
5
Q
Name the insoluble silver compounds.
A
- agcl
- agi (silver iodide)
- agbr (silver bromide)
6
Q
Name the insoluble lead compounds.
A
- pbcl
- pbso4
- pbi
- pbbr
7
Q
Solubility of carbonates, oxides and hydroxides ?
A
carbonate -insoluble except for grp 1and (nh4)2co3
oxides - insoluble except for grp 1 and cao is sparingly soluble
hydroxides - insoluble except from grp 1 ca(oh)2 is sparingly soluble