Exploding Lunch Bag

For those of you who know my kids well, they frequently (always) get into the kitchen, take out different equipment or ingredients and ask (demand) if they can make something.  Last week it was a banana and honey smoothie in the blender - end result was this smoothie for 2... or perhaps for 15!

This week it was the bicarb of soda.  They wanted to make a volcano again... You can imagine my delight when - just five minutes before lunch is ready, I'm finishing the cooking and setting the plates - I hear (on repeat) "I want to make a volcano.. I want to make a volcano.. Muuuumm, I want to make a volcano!" Perfect timing, kids! Thanks!

 It's been a while since we've worked with bicarb so I thought why not?

 

All you need for this one is:
One small zip lock bag
Bicarb of soda
Warm water
Vinegar
Measuring cup
Vinegar

You will need to do this outside - it gets a little messy... and if it's not a good day outside then do it in the kitchen sink or the bath!

Pour 1/4 Cup of warm water into a bag.

Add 1/2 a cup of vinegar into the bag.

Lay the tissue out flat.  Put in 3 teaspoons of bicarb of soda into the middle of the tissue.

Wrap the tissue around the bicarb of soda - only do this lightly - it will help buy you time when you combine the bicarb to the water/vinegar mixture.

Now really quickly zip up the bag and watch what happens!  These pictures were taken the first time we tried the experiment - it didn't work as well as we had hoped but it sure was fun!

 

 

The mixture started fizzing up ...

 

 

The bag started expanding...

 

And expanding - until it got really firm to touch...

 

The kids were so excited but really scared so they kept on running away, waiting for it to explode...

 

Then they ran back to it to see if it did explode...

Until finally we realized the bag had popped - just not how we thought it would! A small hole in the bag- created either by a blade of grass or the fact that the bag had expanded so much that it had ripped the bag.

We did try this experiment again - this time I shook the bag quickly after adding the tissue and bicarb  to the water/vinegar mixture and threw it on the ground (not the grass).  It exploded much more quickly and the boys were absolutely going crazy at what happened - they loved it! If I had more camera battery I could have shown you their faces - they loved it!

Nothing like a little Chemistry to please the senses! What happens inside the bag?  The baking soda and the vinegar eventually mix and when they do mix, you create an acid base reaction and the two chemicals work together to create a gas, (carbon dioxide - the stuff we breathe out). It turns out gasses need a lot of room and the carbon dioxide starts to fill the bag, and keeps filling the bag until the bag can no longer hold it any more and, POP!

Thanks, Science Bob for this cool experiment!

Dancing Sultanas!

This experiment happened after the success of our first experiment DIY crystals.

It was so quick to do and like most of our experiments we had everything we needed in the kitchen already.  Once again, I found this experiment at my favourite site - learning4kids.net

All you need for Dancing Sultanas is a fizzy drink (lemonade is good because you can see through it easily) and some Sultanas.

All you have to do is drop a couple of sultanas - one at a time - into the glass of lemonade.  After a few seconds the bubbles push the sultanas up and it looks like they are dancing!

The boys laughed every time this happened - and is by far their new favourite party trick - they show this to all of their friends when they come over and are just as excited as the first time they did it.  We added a few dried apricots in there as well (we had sultana and apricot packs) but they were too heavy to dance.

 

Even this experiment provided many wonderful learning opportunities - they questioned why the sultanas were dancing, they were taking turns putting the sultanas in the glass, and E even questioned how the bubbles were in the water.  These experiments are so simple, yet the children are having so much fun! I love it!

DIY Crystals!

DIY Crystals

I found this experiment on one of my favourite sites - learning4kids.net - I love their ideas and am always using this site as inspiration for play activities.

To be honest, I wasn't sure how much my boys (3.5 year old and 2.5 year old) would get out of this experiment - they had never really been interested in Crystals before, so I wasn't sure how interesting the experiment would be to them. 
Little did I know how much they would get from it - I can't believe that they are constantly asking for "Bicarbonate of soda" and using the word "dissolve" ALL the time!

• First, we filled two glasses with water. 
• The kids then put  a spoonful of bicarb of soda into their cup, taking turns and sharing the spoon.  It was actually incredible how they were willing to share and follow the "first N then E" rule we had.  They continued this until the bicarb didn't dissolve anymore. 

 

 

Each time they put in a teaspoon of Bicarb of Soda, the water would fizzle and the kids would get so excited - they excitedly made the "fizz" sound themselves and had a good giggle every time they heard it.  They noticed how bubbles formed when they put in the bicarb of soda and this made them even more excited.  The kids were counting how many spoons of bicarb were in there. They were saying "now it's your turn, now it's my turn".  They were telling each other to be careful not to spill the bicarb.  When N had a little sneaky taste of the bicarb, E gently told him to stop doing that because it will make him sick.  It was just so cute.  I love how they were interacting!

• We then tied two paperclips on each end of a long string and placed them in the water.  The hard thing about this experiment is that you had to wait to see results... but having said that our crystals started growing about an hour later - they looked like this:

• We waited a week for our crystals to grow.  Our crystals grew mainly over the glasses and on the bottom of the glass in the water. The kids loved looking and touching them every morning - they went from soft and fragile to quite hard.  Our crystals didn't grow over the string - I think if we had wet the string as well they may had grown... I would be interested to know if anyone does this experiment if their crystals grew on the string and how they did it?? :)

 

• Surprisingly, something else we noticed was that the water in one of the cups turned a beautiful aqua blue - obviously was the colour of the wool we used.  E kept asking why the other glass of water hadn't turned blue!

 

 

Because the kids were so excited about the bubbles in the water, I decided to do another quick experiment with them after the crystals - check out my next Blog entry -

Dancing Sultanas!