Water Flashcards
Order of electronegativity (highest to lowest)
F (highest)
O (very strong)
N (strong)
C H P S (medium)
How do electronegativity differences between atoms dictate bond type?
- Greatest difference = ionic
- Medium difference = polar covalent
- Small difference = nonpolar covalent
What is meant by “bonding occurs on a continuum”?
Not every bonding is strictly ionic or covalent, there can be a mix of both
What atom pairings (between CHNOPS) result in polar covalent bonds?
Different electronegativity
What atom pairings (between CHNOPS) result in nonpolar covalent bonds?
Same electronegativity
How do you determine how a molecule is going to behave with water by looking at its structure?
- Polar atoms surrounding molecule = polar
- Polar on one end = amphipathic
How do each of the following interact with water (ex)
1) (mostly) Polar molecules
2) Nonpolar molecules
3) Amphipathic molecules
4) Ionic substances
1) Attract + mix (water + water)
2) No H bond attraction, some very weak LDF + will mix (2 types of oils, oil + wax)
3) Polar head attract, nonpolar tail repel, polar head mix, nonpolar tail stay separate (water + soap)
4) Attract + mix (salt + water)
What effect does hydrogen bonding have on properties of water and other substances?
- Cohesion
- Adhesion
- Surface tension
- Ice floats
- Dissolving
- Resistance to temp change
What effect does LDF have on properties of water and other substances? What is a LDF?
-Attraction between all matter
-Strongest when particles are closer and as their mass increases
-Creates a weak attraction between molecules
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Why is water a polar molecule? What does this mean?
- O highly electronegative
- H less electronegative
- O attracts more electrons (slightly negative)
- H slightly positive
- Has electrical poles
Hydrogen bonding
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Cohesion (cause and result)
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Adhesion (cause and result)
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Resistance to temperature change (compared to other substances) (cause and result)
-Takes a lot of energy to break hydrogen bonds and get the molecules moving
-Results: ocean acts as buffer to make Earth temp stable, human internal temp stable
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What is temperature a measure of?
-The average kinetic energy of the particles of a substance
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Why does ice float?
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Why is water a great solvent?
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Dissociating vs dissolving
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What effect would soap/detergent have on the properties, of water?
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Polar vs nonpolar
Unequal sharing of electrons vs equal sharing
Specific heat
The amount of energy required to raise the temp of a substance by 1 degree C (water has high SH)
Why are the most electronegative elements at the top right of the periodic table?
- Further right = more electrons = more positive pull to negative electrons
- Further down = more electrons = shielding the pull of the electrons
