Chemical Changes

chemical changes

metal reactivity - in acid

no group 1 = explosive

copper = unreactive

ionic equations

Fe (2+) + Mg (o) — Fe (o) + Mg (2+)

• charges flip

acids

• HCl - chloride

• H(2) SO(4) - sulfate

• HNO(3) - nitrate

• add CuO until in excess

• filter to remove excess

• solution is heated over water (H20) to evaporate water

weak acid

Partially dissociate in solution

Strong acid

Fully dissociate in solution

Titrations

1. acid in burette

2. use pipette to measure base (alkali)

3. place base in conical flask — add indicator, on white tile

4. record starting volume in biruette

Electrolysis

• needs to be liquid so ions can move

• aqueous solution

Na+ — Cl- Cathode = Cl-

H+ — OH- Anode = H+

less reactive

opposites attract

1. least reactive element forms at cathode (H2)

2. halogen always forms

3. No halogen = Oxygen

Electrolysis in aqueous solution - cathode

Factor in water (H2O) ions

• cathode - H+ ions and metal ions present = hydrogen produced

• metal ions = more reactive than H then H produced

• metal ions = less reactive, then a solid layer of pure metal is produced

Electrolysis in aqueous solution - Anode

• Anode - if OH- + halogen ions are present, molecules of chlorine, bromine or iodine will be formed

• if no halogens are present, then the OH- ions are discharged and Oxygen is formed