Thursday, 24 October 2013

It's freezing cold, it's under 70 degrees Celcius! IT'S DRY ICE

Scribe Post 
Oct 24, 2013

Less Dense to Most Dense

What will be the order from top to bottom if saltwater, oil, freshwater and poured into the same test tube?

Quick Summary
  • The order is alcohol, oil, freshwater and saltwater.
  • Oil is less dense than water, so oil always floats on water.
  • Freshwater is less dense than salt water, therefore freshwater floats of saltwater.


How can we easily and safely move water from one tank to another tank?

Quick Summary
  • To move lots of water put a hose in one tank, and put the other end of the hose below the tank.  Suck on one end of the hose and put the other end of the hose where you want the liquid to flow to.
  • Air pressure pushes the water up when you create low pressure in your mouth.
  • Gravity pulls the water down.


    Investigation - What goes from gas to solid?

    Dry Ice Introduction:

    • Do not touch the dry ice for any period over more than 1 second.  

    • Dry ice is solid carbon dioxide.
    • It is less than -79 degrees Celsius!

In your task books: 

Write down possible investigation questions:

Qualitative Observations
Look closely at the dry ice.

  • Observe the ice in general → mist like substance is coming off the solid
  • there are crystals on the sides of the solid

Quickly touch the ice.
  • It’s very cool.
  • It burns if you hold it for a short length of time.
Push the flat edge of the knife into the ice.

  • high-pitched noise
  • knife cools down
  • water condenses on the knife
Push the ice along the try.
  • visible vapour is in the air
Breathe on the dry ice.

  • A lot of gas comes out
When the ice gets smaller, put it into a flask, add some water, and put a cork on top.

  • Gas comes out of the water and the flask
Put your dry ice in the fish tank full of water.

  • It created big bubbles
Put a graduated cylinder full of water upside down on top of a piece of dry ice.  

  • The bubbles are pushing the water up


What happens when you push the flat edge of the knife into the ice?

Dry ice put into the water tank

Water and dry ice mixed in a graduated cylinder

1 comment:

  1. The investigation title should be what goes from solid to gas. Try to label the videos so they match the methods.


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