THSB
Substances, Chemical Reactions, and Conservation of Matter
A pure substance has characteristic properties, such as density, a boiling point, and solubility, all of which a…
Item SB052001: Characteristic properties can be used to identify an unknown solid.
During an activity in science class, a student is given an unidentified white solid. She measures some properties of the solid and lists the properties in the table below.
| Melting point | Soluble in water? | Color | |
| Unidentified solid | 734ºC | yes | white |
Then the teacher gives her the following table that lists the properties for two solids.
| Name of solid (Chemical formula) | Melting point | Soluble in water? | Color |
| Lead Nitrate (Pb(NO3)2) | 270ºC | yes | white |
| Potassium Bromide (KBr) | 734ºC | yes | white |
Could the student’s unidentified solid be either lead nitrate or potassium bromide?
- The unidentified solid could be lead nitrate but not potassium bromide.
- The unidentified solid could be potassium bromide but not lead nitrate.
- The unidentified solid could either be potassium bromide or lead nitrate.
- The unidentified solid could NOT be either potassium bromide or lead nitrate.
Pre-Test
Answer Choice |
Overall |
Grades |
Gender |
Primary Language |
|||
|---|---|---|---|---|---|---|---|
| n = 376 |
6–8 n = 376 |
9–12 n = 0 |
Male n = 206 |
Female n = 170 |
English n = 350 |
Other n = 26 |
|
| A. | 4% | 4% | NAN% | 5% | 3% | 3% | 12% |
| B. | 85% | 85% | NAN% | 85% | 84% | 86% | 73% |
| C. | 8% | 8% | NAN% | 7% | 9% | 8% | 15% |
| D. | 3% | 3% | NAN% | 2% | 4% | 3% | 0% |
Post-Test
Answer Choice |
Overall |
Grades |
Gender |
Primary Language |
|||
|---|---|---|---|---|---|---|---|
| n = 375 |
6–8 n = 375 |
9–12 n = 0 |
Male n = 205 |
Female n = 170 |
English n = 348 |
Other n = 27 |
|
| A. | 3% | 3% | NAN% | 3% | 2% | 3% | 4% |
| B. | 89% | 89% | NAN% | 87% | 91% | 90% | 78% |
| C. | 6% | 6% | NAN% | 8% | 4% | 6% | 11% |
| D. | 2% | 2% | NAN% | 2% | 2% | 2% | 7% |