| time
requ.: |
10 minutes. |
|
objective: |
density
of matter and unit of density (derivated) |
| material: |
|
|
| chemicals: |
Pieces of metal from:
|
- lead
|
|
procedure 1: |
Determine the
volume of the pieces of metal exactly by filling 20ml of water into the
graduated
cylinder, then sliding in each piece carefully and separately. Note the change in volume. |
|
observation 1: |
The weight of
the pieces:
m(Cu)=...........g m(Fe)=..........g
m(Zn)=..........g m(Pb)=..........g
The surface of the liquid rises up to:
V(Cu)=...........ml V(Fe)=..........ml
V(Zn)=..........ml V(Pb)=..........ml |
|
calculation 1: |
d=m/V
d(Cu)=.........g/cm3 d(Fe)=........g/cm3
d(Zn)=........g/cm3 d(Pb)=........g/cm3 |
|
interpretation 1: |
The increase
of the liquid volume is the equivalent of the volume of the metal. |
|
procedure 2: |
Prove the
sclerometric hardness of some metals by scratching one piece of metal
with another one. |
|
observation 2: |
| |
lead |
zinc |
copper |
iron |
| lead |
|
|
|
|
| zinc |
|
|
|
|
| copper |
|
|
|
|
| iron |
|
|
|
|
|
|
interpretation 2: |
Mohs scale:
h(Pb)=1,5 h(Zn)=2,5 h(Fe)=4-5 h(Cu)=3 |
|
source: |
from Barke, H.-D. et al.: One Hundred
Chemistry-Experiments to Avoid Chalk and Talk; University of Muenster,
2004. |
