We realised that we could get an awful lot of particles, in our mixture, out of the water through sieving and filtering.  However, no matter how careful we were and how fine a filter we used, the water would not come clean and clear.

Mr Swallow introduced us to the concept of mixtures and solutions.  Mixtures can be separated by filtering BUT solutions can’t.  Therefore, the dirty water left in our cups after all that sieving MUST be a solution!!!

Mr Swallow challenged us to come up with an experiment to separate the solution and finally purify the water.  We brainstormed all the things we could do to a liquid, we came up with:  pour it (done that), shake it (done that), drink it (errr!!!!), soak it up (good idea), heat it up, cool it down or add something to it.

Each team chose which approach to take and planned their experiment.  Mr Swallow ran around school and popped to the shop at lunch to get all the equipment we needed and off we went.  Investigating whether our idea would separate the solution or not…

Some teams soaked up the water with a sponge or kitchen roll, then squeezed it out to see if that would separate the solution…it didn’t.

Some teams added chemicals, such as Milton, hand sanitizer or washing up liquid, to see if that would work.  It probably killed off any germs but we still wouldn’t want to drink it!

Some teams cooled down the solution by freezing it in an ice cube tray or adding ice to it to “grab” the particles (nice idea as it works with salt if you put too much in your cooking!).  It didn’t work here though!

The final team opted for heating the solution.  They boiled it in a pan on Mr Swallow’s camping stove and as the liquid evaporated into steam, they collected it in half of a bottle (with Mr Swallow’s help and his oven gloves!!!), where it condensed back into clean, clear water!  success!  In order to separate the water from the solution, we had to turn it into a vapour and then back to a liquid.

Well done everyone, we may just survive this journey after all!

 

This morning, Year 4 had a very tricky challenge! We have found out that our water supply on board ship has been contaminated. We need to purify the water so that we can survive the journey.

Mr Swallow got out a bunch of containers, sieves, funnels, colanders, cups cloth and other things and asked us to choose any equipment we wanted for our team. We then had to come up with our own plan about how to use it! What equipment should we use?  How should we use it? What order should we use it in? Our teams discussed what to do and came up with a plan!

 

Down on the field, we experimented with the equipment to try and remove all the horrid things from our cup of water, to make it safe enough to drink!

Some of them worked better than others!

We looked at how the team who had got the cleanest water had done that worked well. They had:

used the filters with the biggest holes first, to get rid of any big particles and not clog up their filter.

worked methodically from large hole filter down to smallest.

worked really carefully, keeping equipment clean and not re-using dirty containers.

Worked patiently, pouring slowly so they didn’t lose any water and giving the water plenty of time to drain through the sieves and muslin.

 

We all adopted their way of working and our results improved dramatically!!!