Paper 6 Essentials

Carbonate (Co3 2-)

Add dilute acid -\> CO2 produced

Chloride (Cl-)

Add HNO3 \> Add AgNO3 \> white ppt. (due to AgCl - Silver Chloride)

Bromide (Br-)

Add HNO3 \> Add AgNO3 \> cream ppt. (due to AgBr - Silver Bromide)

Nitrate (NO3-)

Add NaOH, then Aluminium foil\> WARM carefully \> Produces NH3

Sulfate (SO4 2-)

Add HNO3, then Ba(NO3)2 -\> White ppt. (due to BaSO4 - Barium Sulfate)

Ammonium (NH4+)

Add NaOH: NH3 produced when warmed

Add NH3: No effect

Calcium (Ca2+)

Add NaOH: White ppt insoluble in excess

Add NH3: little / no ppt.

Copper (II) Cu2+ Test using NaOH and NH3

Add NaOH: light blue ppt., insoluble in excess

Add NH3: light blue ppt., soluble in excess \> DARK blue solution

Iron (II) Fe2+

Add NaOH: green ppt., insoluble in excess

Add NH3: green ppt., insoluble in excess

Iron (III) Fe3+

Add NaOH: red-brown ppt., insoluble in excess

Add NH3: red-brown ppt., insoluble in excess

Zinc (Zn2+)

Add NaOH: White ppt soluble in excess \> colorless solution

Add NH3: White ppt soluble in excess \> colorless solution

Ammonia (NH3)

Turns damp litmus paper BLUE

Carbon dioxide (CO2)

Turns limewater MILKY

Chlorine (Cl2)

BLEACHES damp litmus paper

Hydrogen (H2)

'POP' with lit splint

Oxygen (O2)

RELIGHTS glowing splint

Lithium (Li+) -FLAME TEST

Red

Sodium (Na+) -FLAME TEST

Yellow

Potassium (K+) -FLAME TEST

Lilac

Copper (II) 2+ -FLAME TEST

Blue-green

Test for starch

Iodine (goes blue-black)

Test for reducing sugars

Benedict's test. (Add solution, heat in WATER BATH, turns red, low amount \= green, none \= blue)

Test for protein

Biuret solution (turns purple )

Test for fats / lipids

Add ethanol then water (White emulsion)