PROCESS: Determining the Chemical (copy) (copy)
First use a Litmus Test
If Litmus returns Red/Orange:
You have an Acidic Salt formed from a Strong Acid & Weak Base
If Litmus returns Green (Neutral):
You have a Neutral Salt formed from a Strong Acid & Strong Base
If Litmus returns Blue/Purple:
You have a Basic or Alkaline Salt formed from a Weak Acid & Strong Base
STRONG ACID: NO OH GROUPED TOGETHER AND AT LEAST 2 OR MORE O THEN H
STRONG BASE: NO C OR N
Find The Metal Cation (Base)
If the Salt was formed from a Strong Base:
The Metal Cation must be in Group 1 or Group 2, use the solubility table to narrow it down
Some tips:
- Use Sodium Carbonate, if G1, nothing will happen, if G2, a precipitate will form
- If G1 and between Sodium & Potassium, Flame Test Required (Info will be provided)
- If G2, Sodium Hydroxide will determine which metal
If the Salt was formed from a Weak Base:
The Metal Cation must be a Transition Metal, which can be determined with the solubility table to narrow it down (and potentially other properties such as colours and variable solubility)
Find the Anion (Acid)
If the Salt was formed from a Strong Acid:
Recall the Strong Acids (HCl, HI, HNO3, HClO4, H2SO4, HBr), remove the ones that would be impossible (based on solubility), and continue narrowing it down with solubility and colours
Silver Nitrate is great to test for this!
(Silver Chloride would form a White Precipitate)
(Silver Bromide would form a Cream Precipitate)
(Silver Iodide would form a Yellow Precipitate)
If the Salt was formed from a Weak Acid:
Recall the Strong Acids (HCl, HI, HNO3, HClO4, H2SO4, HBr), and remove them, they are not in the realm of possibility. Determine which anion was part of the weak acid by narrowing down more impossible ones using solubility and colours
Additional Tips
MEMORISE THE COLOURS OF PRECIPITATES (Precipitate Colour Flashcards found in this folder)
Anything that isn’t a strong acid or base is a weak acid or base
Strong bases are comprised of a Group 1 or Group 2 Metal + OH
If a substance does not dissolve completely (milky or granular precipitate), it is slightly soluble
If a substance forms a precipitate, but dissolves in excess, it is an amphoteric/amphiprotic substance (Can act as both a weak acid & weak base) This is indicative of a transition meta
First use a Litmus Test
If Litmus returns Red/Orange:
You have an Acidic Salt formed from a Strong Acid & Weak Base
If Litmus returns Green (Neutral):
You have a Neutral Salt formed from a Strong Acid & Strong Base
If Litmus returns Blue/Purple:
You have a Basic or Alkaline Salt formed from a Weak Acid & Strong Base
STRONG ACID: NO OH GROUPED TOGETHER AND AT LEAST 2 OR MORE O THEN H
STRONG BASE: NO C OR N
Find The Metal Cation (Base)
If the Salt was formed from a Strong Base:
The Metal Cation must be in Group 1 or Group 2, use the solubility table to narrow it down
Some tips:
- Use Sodium Carbonate, if G1, nothing will happen, if G2, a precipitate will form
- If G1 and between Sodium & Potassium, Flame Test Required (Info will be provided)
- If G2, Sodium Hydroxide will determine which metal
If the Salt was formed from a Weak Base:
The Metal Cation must be a Transition Metal, which can be determined with the solubility table to narrow it down (and potentially other properties such as colours and variable solubility)
Find the Anion (Acid)
If the Salt was formed from a Strong Acid:
Recall the Strong Acids (HCl, HI, HNO3, HClO4, H2SO4, HBr), remove the ones that would be impossible (based on solubility), and continue narrowing it down with solubility and colours
Silver Nitrate is great to test for this!
(Silver Chloride would form a White Precipitate)
(Silver Bromide would form a Cream Precipitate)
(Silver Iodide would form a Yellow Precipitate)
If the Salt was formed from a Weak Acid:
Recall the Strong Acids (HCl, HI, HNO3, HClO4, H2SO4, HBr), and remove them, they are not in the realm of possibility. Determine which anion was part of the weak acid by narrowing down more impossible ones using solubility and colours
Additional Tips
MEMORISE THE COLOURS OF PRECIPITATES (Precipitate Colour Flashcards found in this folder)
Anything that isn’t a strong acid or base is a weak acid or base
Strong bases are comprised of a Group 1 or Group 2 Metal + OH
If a substance does not dissolve completely (milky or granular precipitate), it is slightly soluble
If a substance forms a precipitate, but dissolves in excess, it is an amphoteric/amphiprotic substance (Can act as both a weak acid & weak base) This is indicative of a transition meta
