Question 34
The type of polymer in plastic container can be identified by observing the floating and sinking of the unknown polymer in the liquid of known density. From the result of the density test, what could be the identity of the unknown plastic? (1 point)
| Liquid | Composition | Density (g/cm³) | Polymer | Density range (g/cm³) |
| --- | --- | --- | --- | --- |
| 1 | Ethanol | 0.79 | PP - polypropylene | 0.90–0.91 |
| 2 | 50% v/v ethanol/water | 0.91 | LDPE - low density polyethylene | 0.92–0.94 |
| 3 | Water | 1.00 | HDPE - high density polyethylene | 0.95–0.96 |
| 4 | 6% CaCl₂ in water | 1.05 | PS - polystyrene | 1.04–1.06 |
| 5 | 32% CaCl₂ in water | 1.30 | PVC - polyvinylchloride | 1.16–1.58 |
| Liquid 1 | Liquid 2 | Liquid 3 | Liquid 4 | Liquid 5 |
| --- | --- | --- | --- | --- |
| Sink | Sink | Float | Float | Float |
| Liquid | Composition | Density (g/cm³) | Polymer | Density range (g/cm³) |
| --- | --- | --- | --- | --- |
| 1 | Ethanol | 0.79 | PP - polypropylene | 0.90–0.91 |
| 2 | 50% v/v ethanol/water | 0.91 | LDPE - low density polyethylene | 0.92–0.94 |
| 3 | Water | 1.00 | HDPE - high density polyethylene | 0.95–0.96 |
| 4 | 6% CaCl₂ in water | 1.05 | PS - polystyrene | 1.04–1.06 |
| 5 | 32% CaCl₂ in water | 1.30 | PVC - polyvinylchloride | 1.16–1.58 |
| Liquid 1 | Liquid 2 | Liquid 3 | Liquid 4 | Liquid 5 |
| --- | --- | --- | --- | --- |
| Sink | Sink | Float | Float | Float |