Required practicals 🥼🧪 Flashcards
What is a [short and basic] method to produce, pure dry crystals?
Hint: dilute solution, filtered off, saturated solution heated and warm place.
1) excess [magnesium carbonate) added to dilute solution, until no more dissolves. (Shows no more is reacting).
2) excess magnesium carbonate is flitered off.
3) saturated solution heated for a few minutes (to evaporate some of the water).
4) leave in a warm place until dry crystals are formed, or until the crystals can be dried on fliter paper.
What’s a key feature about a salt ?
- a salt, always contains a positive ion.
- For example in copper sulphate, the positive ion is the metal ion: Cu2+
- ; salts also contain a negative ion. For example, in copper sulphate: SO4^2-
What is a full method to produce, pure dry crystals?
Hint: dilute solution, filtered off, saturated solution heated and warm place.
1) start with a fixed volume of dilute sulcuric acid-[this is our limiting reactant]
2) then gently heat the acid, until almost boiling.
3) using a spatula, add small amounts of copper oxide to the acid and stir the solution sith a glass rod. [solution should turn blue and copper oxide should seem to dissapear]
4) if the solution contuines to be clear blue, contuine adding copper oxide and stop adding copper oxide, if some powder remains after stirring.
5) unreacted copper oxide is flitered off, using a filter funnel and filter paper
6) place the solution in an evaporating basin and heat gently over a beaker of boiling water- heat until half of the solution remains
7) then leave the solution for 24 hours, in a cool palace for copper sulphate crystals to form.
8) finally, scrape the crystals on get paper towel and gently pat them dry.
