Chapter 2 Pt 1 Flashcards
(18 cards)
What is CHOPKINS?
Carbon, Hydrogen, Oxygen, Phosphorus, Potassium, Iodine, Nitrogen, Sulfur
An element has a unique number of what?
Protons
What do valence electrons do for atoms?
They make atoms more reactive
When does a chemical reaction occur?
When bonds are made or broken
What is a covalent bond? Explain the difference between nonpolar and polar bonds
A covalent bond is when electrons share molecules.
Nonpolar bonds share electrons equally
Polar bonds share electrons unequally
What is electronegativity?
Affinity of an atom to attract electrons to itself.
Is this the correct electronegativity (O>N>C=~H)?
Yes
What is molarity?
Number of moles over volume
M=#ofMoles/Volume
What are 4 properties that make water important?
- Water is an excellent solvent
- Water must be: adhesive, cohesive, and have a high level of surface tension
- Liquid water is denser than ice
- Water has a high specific heat and heat of vaporization
Why is water an excellent solvent?
Because water polar and forms hydrogen bonds with itself.
Describe the differences between hydrophilic and hydrophobic.
Hydrophilic- “Water-Lover”; substances (ions and polar molecules) dissolve in water.
Hydrophobic- “Water-Hater”; substances (large, nonpolar molecules) do not dissolve in water.
What does cohesive and adhesive mean?
Adhesive- binding between unlike molecules.
Cohesion- binding between like molecules.
Why is water denser than ice?
In ice, water molecules from a crystal lattice. In liquid water, no crystal lattice forms.
Why does water have a high specific heat?
High specific heat of water is due to the strength of H-bonds.
What is specific heat?
Amount of heat needed to raise the temperature of 1 gram of water.
Why does water change temperature very slowly?
- Water temperature is more stable than air temperature.
2. Water has a high heat of vaporization.
What does “heat of vaporization” mean?
Amount of heat a liquid must absorb to convert 1g of the liquid to gas
What do acid & bases do?
Acids increase the “H+” concentration in water.
Bases decrease the “H+” concentration in water.
