explainations

[naved_s9994]

Hi everyone, 

*Water* *AOS1 Unit 2* - VCE Chemistry Unit 2

I know how to explain that when ice melts the can 'fall' into the 'gaps' in a highly ordered
arrangment and hence pack more closely. Thus liquid is denser. But how can I explain
that Ice is less denser in a similar format (Lets say Liquid to Ice)

Also can anyone explain the reason why there is high surface tension

[naved_s9994]

Also how to explain that it expands when freezes?? !!

[thisongaintgottaname]

how can I explain that Ice is less denser in a similar format (Lets say Liquid to Ice)

this links back to why water expands when it freezes.

Also how to explain that it expands when freezes?? !!

Its mainly due to the hydrogen bonding, as the highly directional nature of this bonding causes water molecules to take up an interconnected open ring structure in the solid. and When ice is melted, the water molecules have enough energy to overcome many of the hydrogen bonds and move out of these rings and past one another. they are still attracted to each other thoug, so hydrogen bonding is still able to operate to an extent, and the water molecules are able to move closer.

explain the reason why there is high surface tension

For this one, you could think this way, the intermolecular bonding in water is stronger than other liquids, so there is a net pull on each molecule in its surface, and it is quite significant. Thats why they can support objects on the surface like a shield of skin. This is the surface tension, and basically, it is the net force of attraction per metre lenth of surface. ( this is why droplets of water is spherical, because each molecule is pulling on each other and is being drawn towards the centre of the water by allll the water molecules beneath it.

[naved_s9994]

Welcome to VN!
and thanks soo much !