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Chapter 10
Lime
| Question | Answer |
|---|---|
| Uses of limestone | blocks for buildings, lime for mortar, concrete |
| Who discovered concrete and when? | Romans, 200BC |
| Uses of gypsum | Plaster, stucco, sheetrock |
| When was plaster discovered? | ~7000BC |
| What family of minerals is gypsum from? | CaSO4 |
| Anhydrite | CaSO4 |
| Bassanite | CaSO4 . 1/2H2O aka plaster |
| gypsum | CaSO4 . 2H2O aka alabaster |
| How does gypsum become plaster? | Heated to 128C CaSO4.2H20(s)=CaSO4 .1/2H20(s)+3/2H20(l) |
| Plaster becomes anhydrite at... | 168C CaSO4.1/2H20(s)=CaSO4+1/2H20(l) |
| Anhydrite slowly reconverts to plaster... | CaSO4(s)+1/2H20(s)=CaSO4.1/2H20(s) |
| Plaster quickly reconverts to gypsum | CaS04.1/2H20(s)=CaS04.2H20(s) |
| Family of minerals that limestone is from... | CaCO3 |
| calcite and aragonite | CaCO3 (atoms arranged slightly differently) |
| dolomite | CaCO3.MgCO3 |
| Limestone comes from... | sediment, seashells, insoluble in water |
| Limestone to quicklime | CaCO3(s)=(burn)CaO(s)+CO2 |
| Quicklime to slaked lime | CaO(s)+H2O(l)=Ca(OH)2(s) |
| slaked lime and carbonic acid | limestone |
| Carbonic acid | H2CO3 |
| process schematic | go look, silly |