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Properties of Water

What-er weird molecule

Water is all around us…but have you ever stopped to think about

it?

1. Specific Heat2. Polarity 3. Density

As Matt Smith would say… (very very strange)

Properties of Water

Specific Heat - the amount of heat required to raise the temperature of a set, or standard, amount of matter by one degree Celsius

Ex. At 35 °C Specific Heat of:Water - 4.185 KJ/KgKPeanut Oil - 2.095 KJ/KgK

Specific Heat

* KJ/KgK = Kilojoule per Kilogram x °Kelvin

Specific HeatWhat in the world does that mean!?

If the water is 60 °C… And you have 1 kg of water… You would need 4.185 KJ of energy to

increase the temperature by 1 measly degree Celsius!

A 40 Watt light bulb uses 3,456 KJ if left of for 24 hours

Polarity Polarity - the state of having two opposite or contradictory sides

Why would water be considered polar?

Hint:

Bigger Hint

Polarity Polarity causes water to do some REALLY weird things…

Maybe not that weird…Or that weird……But it does allow it to: 1. flow against gravity2. Let things walk on its liquid surface

a) Jesus Lizard3. Change its density in a way that no other

substance really does.

Polarity

Adhesion vs. Cohesion

Cohesion – The act of two pieces of the same substance sticking together

when H2O “sticks” together with more H2O

Adhesion – The act of two different substances sticking together

when water and something else “stick” together

Polarity Cohesion

Responsible for SURFACE TENSION What is Surface Tension? (No really, ask

me!) http://

water.usgs.gov/edu/surface-tension.html

Surface Tension – (You tell me!)

Surface Tension – A barrier on the uppermost layer of water that is difficult to penetrate until broken. It is created by a strong cohesive force between the top layer of water molecules.

Polarity Just how strong is the force of cohesion in surface tension?

PENNY LAB!

Polarity Penny Lab!!1. With the person next to you (let Mr. H pair you).2. Person 1 fill a beaker with water and obtain a

penny & eye dropper.3. While Person 1 is collecting materials, clear your

desk space and make a hypothesis of how many water drops will fit on the surface of a penny.

4. Fill your eye dropper with water and gently drip drops of water onto the penny (BE CARFUL TO NOT BUMP THE TABLES!)

5. Count how many drops fit on top of the penny.6. Clean your lab station and answer this question:

• In your own words, how strong is the force of cohesion in water tension?

Polarity Adhesion creates capillary action

Go ahead, ask me what it is!Pretty please!With sugar on top? And rainbow sprinkles!?I’m soooooo glad you asked!http://water.usgs.gov/edu/capillaryaction.html

Capillary Action – the movement of water within the spaces of a porous material due to the forces of adhesion, cohesion, and surface tension.

Examples:1. Water climbing your graduated cylinder…

Pretty Please

Polarity Water is the UNIVERSAL SOLVENT

Solvent – A substance that does the dissolvingSolute – A substance that gets dissolved

It’s because of an uneven distribution of electrons!

Polarity Water is the UNIVERSAL SOLVENT

Soil is charged too! That’s why soil gets carried away when it rains!

This can create rivers!!(change powerpoint Mr. H!)

Polarity

Water density graphing activity!