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27 Cards in this Set
- Front
- Back
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What is the electronegativity and how does it affect interactions between water molecules |
Electronegativity is the attraction of an atom for the electrons of a covalent bond. Because oxygen is more electronegative than hydrogen, the oxygen atom in h2o pools electrons towards itself, resulting in a partial negative charge on the oxygen atom and partial positive charges on the hydrogen atoms. Atoms in the neighboring water molecules with opposite partial charges are attracted to each other, forming a hydrogen bond. |
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Why is it unlikely that two neighboring water molecules would be arranged like this: with the hydrogens attracting each other. |
The hydrogen atoms of one molecule, with their partial positive charges, would repel the hydrogen atoms of the adjacent molecule. |
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What would be the effect on the properties of the water molecule is oxygen and hydrogen had equal electronegativity? |
Because ailent bonds of water molecules would not be polar, and water molecules would not form hydrogen bonds with each other. |
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Each water molecule is joined to blank other water model molecules by blank bonds |
4, hydrogen |
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The unequal sharing of electrons within a water molecule makes the water molecule what |
Polar |
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The tendency of an atom to pull electrons towards itself is referred to as its |
Electronegativity |
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Ball oxygen shares electrons with hydrogen, the electrons spend more time with |
Oxygen than with hydrogen |
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Hydrogen bonds are weaker than covalent bonds because they do not involve sharing of electrons, and they are weaker than ionic bonds because they involve the attraction of |
Partial opposite charges |
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What allows insects to remain on the surface of water |
Surface tension |
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a relatively large amount of heat must be added or removed in order to get the temperature of the water to change significantly |
Water has a high specific heat |
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Vaporization |
Molecules move fast enough to overcome their attractions, due to hydrogen bonding, and depart from liquid and enter the air as gas |
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At what temp does vaporization occur |
Any temp, however, heat increases the rate |
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Heat of vaporization |
The amount of heat a liquid must absorb for 1g to be converted from liquid to gas |
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Evaporative cooling |
As liquid evaporates the surface of liquid remains cool |
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Why does ice float |
Water expands when frozen. Making it less dense due to hydrogen bonding |
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Solution |
Liquid, completely homogeneous mixture of 2 or more substances |
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Solvent |
The dissolving agent |
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Solute |
The substance dissolved |
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Hydration shell |
Water molecules surround the dissolved ions |
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Colloid |
A stable suspension of fine particles in a liquid, lime milk or jello |
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How many molecules are in one mole |
6.02 × 10 (23) |
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Molarity |
Numbers of moles of solute per liter of solution |
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Acid |
A substance that increases the hydrogen ion concentrations of a solution |
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Base |
A substance that reduces the hydrogen ion concentrations of a solution |
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The product of H+ and OH- of an aqueous solution at room temp is |
10 (-14) no matter what. If 10 (-7) H+ then 10 (- OH-, if 10 (-5) H+ the 10 (-9) OH- thus always 10 (-14) |
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PH scale |
Low PH high acid, high PH low acid (or high base) |
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Buffer |
Substance that minimizes changes in the concentration of OH and H in solutions |
