Chemistry rev - salt preparations

how to prepare a pure, dry sample of an insoluble salt :

  1. mix together two soluble salts + stir the mixture

  2. filter the mixture through a filter paper to separate the insoluble salt from the aqueous solution.

  3. wash with distilled water to remove soluble impurities

  4. pat dry with a clean paper towel to ensure that no moisture remains before proceeding to store or use the dry solid.

How to prepare a pure, dry sample of a soluble salt from an excess metal oxide and a solution :

  1. add the excess metal oxide to solution

  2. warm solution

  3. filter solution to remove excess

  4. heat filtrate to remove some of the water

  5. cool to crystallize

  6. pat dry

How to obtain a soluble salt from a solution :

  1. gently heat to evaporate some of the water

  2. leave the solution to cool & crystallize - crystals will form as as it cools it becomes less soluble

  3. filter off crystals

  4. leave crystlas to dry and blot dry

Sulfur dioxide is acidic - forms acid rain

homologous series = elements of same functional group with same trends in physical properties such as boiling and melting points, and similar chemical behavior. - each member differs by CH2

explain ionic bonding in sodium oxide = electrostatic attraction between two shared ions in which sodium ions (Na+) and oxide ions (O2-) are attracted to each other due to their opposite charges, resulting in a stable ionic compound. The lattice structure formed in sodium oxide enhances its overall stability and contributes to its high melting and boiling points.

electrolysis of aqueous sodium chloride =

H+, OH-, Na+, Cl-

chlorine + sodium = the reaction produces chlorine gas (Cl2) at the anode, while sodium ions (Na+) migrate towards the cathode, where they can combine with water to form sodium hydroxide (NaOH). This process demonstrates the principles of electrolysis as it separates the components of the compound based on their ionic properties. The production of hydrogen gas (H2) occurs at the cathode, completing the overall reaction of generating chlorine gas and sodium hydroxide through the electrolysis of sodium chloride.

4OH- —> 2H20 + O2 + 4e- = need to learn

tests for :

H2 = lit splint burns with a squeaky pop

CO2 = limewater turns milky when CO2 is bubbled through it.

O2 = relits a glowing splint

NH3 = litmus paper goes from red to blue

Cl2 = turns damp litmus red then bleaches it

I Never Bring Classwork Home On Fridays - I2,N2,B2,Cl2,H2,O2,F2