Bio 1 1
Lab#3: Water Lab
Important Word Roots
Water
• Old English w æterian "moisten”
www.ces.fau.edu
Polar • Latin polus "an end of an axis
+/-­‐
www.personal.psu.edu
Hydrogen Bonding • Hydro = w ater • Joined
• *gen = a combining form meaning “that which produces”
Polar, Non Polar and Amphipathic • Polar • Non-­‐Polar • Amphipathic
• Combining Form • Experience www.marin.edu
www.york.ac.uk
Water ’s Life Supporting Properties
The S heer Awesomeness that are Hydrogen Bonds
1. Water m olecules stick together.
2. Water has a strong resistance to change
in temperature.
3. Frozen water floats.
4. Water is a common solvent for life.
Proff. Zannie Dallara 1
Bio 1 1
Lab#3: Water Lab
Water as the Solvent of Life
– A solution is a liquid consisting of a homogeneous
mixture of two or more substances.
• The dissolving agent is the solvent.
• The dissolved substance is the solute.
– When water is the solvent, the result is an aqueous
Salt crystal
Sodium solution.
ion in solution
Na+
Na
+
Cl–
Cl–
Chloride ion in solution
© 2 0 1 3 P earso n Ed u catio n , In c.
How do A mphipathic Molecules Work in a world full of water? How about cell membranes?
Important Word Roots
Adhesion Cohesion Capillary Action • French adhésion = • French cohésion • Capillaris "of hair”
= sticking sticking t o • Action = Move
together
Add to another Water sticking to substance
water
http://water.usgs.gov/edu/adhesion.html
springtolife.weebly.com
Proff. Zannie Dallara 2
Bio 1 1
Lab#3: Water Lab
Important Word Roots
Hydro
• Water
*Phylic
• Loving
*Phobic
• Fearing
A charge is what makes something hydrophilic
Water’s Life-­‐S upporting Properties
• The polarity (charge) of water molecules and the hydrogen bonding that results explain most of water’s life-­‐supporting properties.
1. Water molecules stick together.
2. Water has a strong resistance to c hange in temperature.
3. Frozen water floats.
4. Water is a common solvent for life
www.ces.fau.edu
Why do you care about water? www.kidsworldfun.com
Proff. Zannie Dallara 3
Bio 1 1
Lab#3: Water Lab
Water’s Life-­‐S upporting Properties
– The polarity ( charge) of water molecules and the hydrogen b onding that results explain most of water’s life-­‐supporting p roperties.
1) Water molecules stick together.
–AKA Cohesion http://water.usgs.gov/edu/adhesion.html
1) Water molecules stick together.
Surface tension is the measure of how difficult i t i s to stretch or break the surface of a liquid.
• Hydrogen b onds give water an u nusually h igh surface tension.
Water’s Life-­‐S upporting Properties
– The polarity ( charge) of water molecules and the hydrogen b onding that results explain most of water’s life-­‐supporting p roperties.
2) Water has a s trong resistance to change in temperature.
–Hydrogen bonds build and reform easily Proff. Zannie Dallara 4
Bio 1 1
Lab#3: Water Lab
Water’s Life-­‐S upporting Properties
– The polarity (charge) of w ater molecules and the hydrogen bonding t hat results explain most of water’s life-­‐supporting properties.
3) Frozen water floats.
• Cold = Moves slower = all hydrogen bonds met = each molecule is farther apart = less dense = floats Water’s Life-­‐S upporting Properties
– The polarity (charge) of w ater molecules and the hydrogen bonding t hat results explain most of water’s life-­‐supporting properties.
4) Water is a common solvent for life.
Water as the Solvent of Life
– A solution is a liquid consisting of a homogeneous (looks the same throughout) mixture of two or more substances.
• The dissolving agent is the solvent.
• The dissolved substance is the solute.
– When water is t he solvent, t he result is an aqueous solution.
Salt crystal
Sodium ion in solution
Na
+
Na
+
–
Cl
Cl–
Chloride ion in solution
Proff. Zannie Dallara 5
Bio 1 1
Lab#3: Water Lab
Other Molecules Detergent -­‐
ßHydrophilic ßHydrophobic www.york.ac.uk
Other Molecules Oil
ßHydrophilic ßHydrophobic wps.prenhall.com
www.emec.com.eg
Start W ith A ctivity 4
It needs to get in the freezer so we start it • Each group: 1. 1 t est t ube rack 2. 2 t est t ubes 3. Measure 10mls of ice cold water into each of your t est t ube 4. Label test t ubes (tape) 1.
2.
3.
Label 1: Room Temp Label the Other: Freezer
Label both with team name/symbol 5. Measure/record the height of the w ater in each t ube (in mm)
6. Put t hem in t he group rack
•
1 will go in the freezer, 1 wont Proff. Zannie Dallara 6
Bio 1 1
Lab#3: Water Lab
Build 3 Marshmallow W ater Molecule • Build 3 water molecules: – 3 Large M arshmallow = Oxygen • Label w ith atom and charge Oxygen
-­‐
– 6 s mall marshmallows = H ydrogen – Label with atom and charge •
•
6 t oothpicks = polar covalent bonds
3 strings = H bonds – D rop them and add their interactions
– Get signed off
www.science-­‐sparks.com
Balloon •
•
•
•
•
Beaker full of water
Cork with tube Blow up balloon Tie it off
Rub it on your head (20-­‐30 www.dailymail.co.uk
sec) • Remember where the spot it rubbed was • Move close to stream of poring water Race!
• Oil • Water • Strip of paper
• Dip and race up the paper • Observe and t ry t o figure out w hat is happening Proff. Zannie Dallara 7
Bio 1 1
Lab#3: Water Lab
Cutouts and lay out like it would look • Get me to sign off before gluing down Soda
• Try to figure out the: – Solvent – Solute – Solution Capillary Action • Skinny tube • Touch tube to drop of water on desk
• Shake out the water
• Do that a couple times • Record observations • Answer questions Proff. Zannie Dallara 8