|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
 |
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
| This
is Jurong Frog Farm. Here we got our tadpoles. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
| We
mixed the pondwater with the acids/akalis and then measured the
pH values of the solution. If the pH value was not what we wanted,
we either added in more pondwater or more chemicals. |
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| After
we mixed the solutions, we poured the solutions/pondwater in round
bottom plastic containers. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Then
we put 5 tadpoles in each container. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Below
are some pictures of the tadpoles at the start of the experiment.
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Pondwater
cum hydrochloric acid |
| (pH
4.0 and 5.5) |
|
|
|
|
|
|
|
|
|
|
|
| Control
pondwater (pH7.0) |
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Pondwater
cum nitric acid |
| (pH
4.0 and 5.5) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Pondwater
cum sulphuric acid |
| (pH
4.0 and pH 5.5) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Pondwater
cum ammonium hydroxide (pH 8.5 and 10.0) |
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
| Pondwater
cum calcium hydroxide |
| (pH
8.5 and 10.0) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Pondwater
cum sodium hydroxide |
| (pH
8.5 and 10.0) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|