Activity
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Drought is a major issue in Australia. Sodium polyacrylate may be used as a soil wetting agent, able to attract and retain water before it runs off.
It is important to see if :
- the salt in the soil influences the amount of water that can be attracted;
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the water that is attracted to the sodium polyacrylate is available for plants. |
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| Design an investigation to answer the questions above. |
| A student performed the experiment mentioned above. He potted 15 identical tomato plants in identical containers in normal potting mix and in potting mix with 20% by mass hydrated gel. The pots with hydrated gel are on the right. Each batch was watered fully and the water allowed to run off. The tubs were left for several days. |
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| The results after 14 days. |
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| The plants with the hydrogel have obviously survived better. |
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| The pots with normal potting mix have not survived as well as those with the hydrogel. |
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Can plants get access to the trapped water?
What uses can you envisage?
Would this hydrogel be useful to hydrate football fields? Explain |