[공학]칼륨명반중 알루미늄 정량

소개글

칼륨명반중 알루미늄 정량

목차

1 Title
2. Date
3.Theory
4. Apparatus & Reagent
5. Process
6. Results
7. Error factor
8. Description

본문내용

3.Theory
1) What`s potassium alum
Potassium alum or potash alum is the potassium double sulfate of aluminium. Its chemical formula is KAl(SO4)2·12(H2O). It is commonly used in water purification, leather tanning, fireproof textiles, and baking powder.

2) Al3+ + OH- → Al(OH)3↓
NH3․H2O ⇆ NH4+ + OH-

3) Why we use NH4NO3 to wash the Al(OH)3
Al(OH)3↓ + 3NH4NO3 → Al(OH)3↓ + 3N2O + 6H2O
Mechanism
Al3+ + 3OH- → Al(OH)3↓
2Al(OH)3 → Al2O3 + 3H2O


4. Apparatus & Reagent
1) Apparatus
Watch glass
Beaker (300㎖)
Desiccator
Crucible
Funnel
5. Process
1. AlK(SO4)2·12H2O 0.5g + H2O 100ml in beaker →heating
2. add 1N NH4Cl 50ml + 0.2% methyl red (pH (red)4.2~ 6.2(yellow))
3. + 6N NH4 1dropping ( if red→yellow, 1~2min heating → precipitation filter)
4. wash by 2% NH4NO3 gather filter bed
5. + 1N BaCl2 (check white precipitation)
6. if not, drying 100~110℃ →put crucible
7. heating (slowly→hardly)→cooling in desiccator
8. weight

참고 자료

없음