A look at dissolving

We took a look at 6 different brown-coloured materials to see whether or not they dissolved in water. We chose brown powder paint, sawdust, brown sugar, sand, instant coffee and ground coffee.

We planned a fair test. We made it fair by using the same amount of water, using the same amount of each material and by stirring each the same number of times.
We described what we noticed when we looked carefully at each beaker.

This is what Isabella noticed straightaway:



By the next day we saw that some things had changed.
Most of the brown powder paint had sunk.....



The sawdust had mostly sunk (Per said this was probably because the wood had soaked up water and got too heavy to float).....



The brown sugar had stayed the same; it had turned the water brown and disappeared completely (or dissolved) straightaway.....



The sand had stayed the same - it had sunk straightaway (Max said he knew this would happen because when you go to the beach, the sand is always at the bottom of the sea).....



The instant coffee had stayed the same; it had turned the water brown and disappeared completely (or dissolved) straightaway.....



The ground coffee had turned the water brown and the grains had sunk.....



We also took a look at different white-coloured materials to see whether or not they dissolved in water. We chose white powder paint, cornflour, sugar, salt and chalk.

We planned a fair test. We made it fair by using the same amount of water, using the same amount of each material and by stirring each the same number of times.
We described what we noticed when we looked carefully at each beaker.

This is what we noticed straightaway:

We thought the white powder paint had dissolved - it turned the water white, just like paint.



We thought the cornflour had dissolved - it turned the water white (just like paint!)
Some of the chalk had floated, but it had also made the water go cloudy.
We thought some of the sugar might have dissolved, but there were some grains on the bottom of the beaker.
Most of the salt had sunk; we saw the grains on the bottom of the beaker.

By the next day we saw that some things had changed.
Most of the white powder paint had sunk.....



Most of the cornflour had sunk.....



Most of the chalk had sunk.....



The sugar had disappeared completely (or dissolved).....



The salt had disappeared completely (or dissolved).....



We wondered where the salt had gone; it had disappeared completely (or dissolved) which meant we could not see it. So where was it?

Why not ask our brave 'guinea-pig', Patricia? She did the taste test for us.....



"Ugh," she spluttered. "Salty water!"