Examples of precipitate in the following topics:
-
- Precipitation reactions transform ions into an insoluble salt in aqueous solution.
- Precipitation refers to a chemical reaction that occurs in aqueous solution when two ions bond together to form an insoluble salt, which is known as the precipitate.
- The following is a common laboratory example of a precipitation reaction.
- A final way to represent a precipitation reaction is known as the net ionic equation.
- Distinguish ways to write precipitation reactions (complete ionic equation and net ionic equation) and use a solubility table to determine whether a precipitation reaction will occur
-
- Silver chloride (AgCl) is not soluble and forms a white precipitate.
- So how does one tell if the precipitate is a carbonate or a chloride?
- If the precipitate remains unchanged, then the salt is a chloride.
- Bromides and iodides also form precipitates when they are reacted with silver nitrate, but both precipitates are pale yellow.
- Which ion will precipitate first?
-
- Sometimes ions in solution react with each other to form a new substance that precipitates; this reaction is called a precipitation reaction.
- A precipitate, which looks like light blue specks of dust, forms.
- No precipitate forms.
- Therefore Na2CO3 will remain in solution, but CuCO3 will precipitate out.
- This is why no precipitate forms in this second reaction.
-
- Two common techniques are precipitation analysis and colorimetric analysis.
- The color of the precipitate will indicate the metal.
- Barium, calcium, and strontium will precipitate at this point, but not before.
- However, precipitation methods similar to those mentioned above are often used.
- Difference in the visual appearance of an aggregate and a precipitate.
-
- Solubility-product constants can be used to devise methods for separating ions in a solution by selective precipitation.
- Selective precipitation is used to form a solid with one of the ions in solution without disturbing the other ions.
- Can either Ba2+ or Sr2+ be precipitated selectively with concentrated sodium sulfate (Na2SO4) solution?
- Which ion will precipitate first?
- Precipitation is used in qualitative chemical analysis.
-
- Precipitation reactions can be written as molecular, ionic, or complete ionic equations.
- There are various ways to write out precipitation reactions.
- On the right hand side of the equation, the precipitant (AgCl) is written in its full formula and designated as a solid, since this is the precipitate that is formed in the reaction.
- In this representation, the ions that are uninvolved in the precipitation reaction ($Ca^{2+}$ and $NO_{3}^{-}$) are simply excluded from the reaction, because they are essentially redundant on both the left and right side.
- Silver chloride is a precipitant of silver and chloride ions reacting in solution.
-
- Adding a common ion decreases the solubility of a solute, causing it to precipitate.
- When equilibrium is shifted toward the reactants, the solute precipitates.
- In the water treatment process, sodium carbonate salt is added to precipitate the calcium carbonate.
- The very pure and finely divided precipitate of calcium carbonate that is generated is used in the manufacture of toothpaste.
- Lithium hydroxide forms less-soluble lithium carbonate, which precipitates because of the common ion effect.
-
- Adding aqueous sodium hydroxide causes the precipitation of light blue solid copper (II) hydroxide.
- Aqueous ammonia results in the same precipitate.
- Upon adding excess ammonia, the precipitate dissolves, forming tetraamminecopper (II):
- Aqueous ammonia results in the same precipitate.
- Upon adding excess ammonia, the precipitate dissolves, forming tetraamminecopper(II):
-
- In a reaction in which a precipitate is formed, the amount of precipitate formed in a period of time can be used as a measure of the reaction rate.
- For example, when sodium thiosulphate reacts with an acid, a yellow precipitate of sulfur is formed.
- However, as the reaction progresses and more precipitate is formed, the cross will gradually become less clear and will eventually disappear altogether.
- By using a stopwatch to time how long it takes for the cross to disappear, and then massing the amount of precipitate formed during this time, an average reaction rate can be calculated.
-
- This deep blue reagent is reduced to cuprous oxide, which precipitates as a red to yellow solid.
- To avoid precipitation of the insoluble metal hydroxides, the cations must be stabilized as complexed ions.