Week 2 - Chemisty Part 2 Flashcards
Electronegativity
Tendency to attract a bonding pair of electrons
More electronegativity in one atom =
greater pull of another atom towards it
electronegativity = polarity
molecules have atoms with different levels of
Weak interactions: polarity
when the electron are pulled to one side of the molecule preferentially
Weak interactions: small weak charge
(not a true molecular charge) that happens within the molecule
When molecules are completely balanced / neutral, often symmetrical
They have no polarity = NO POLAR MOLECULES
What is Hydrogen bonding
when the hydrogen on one molecule weakly attracts to an electronegative atom on another polar molecule
(it’s like 2 separate families that like to hang out)
what atoms will hydrogen attract to on?
- other polar molecule
- oxygen
- nitrogen
- sulfur
what are the unique properties of water?
- liquid and gas at room temp
When water molecules stick together quite effectively
high surface tension
True or false, liquid water is able to change temperatuure quickly
FALSE
Vaporization requires a ____ of _____
lot, heat
T/F - Frozen wter is less dnese than liquid water, why
true, it expands and floats
water is a great _____ for _____ molecules
solvent, polar
- if its polar then water will accept it
What are the properties of water
- Cohesion
- Adhesion
- Capillary action
water cohesion
attraction of molecules to other molecules to the same type
water adhesion
attraction of molecules to other molecules of a different kind
capillary action in water
water pulls up a glass (capillary) tube quite easily - water is attracted to the glass walls
What are chemical reactions?
They are the making and breaking of chemical bonds
What are the starting molecules of a chemical reactions called, left or right side?
reactants
The final molecules of a chemical reaction are called, left or ride side?
products
An ‘arrow’ represents what in a chemical reaction
yield
coefficients represent how many _____ are in each reaction
molecules
subscripts represent how many _____ are in each molecule
atoms
What is the pH scale
A scale of 0-14 - measures how many protons (H+) are in a solution
pH greater than 7.0
Acid
pH less than 7.0
Basic
pH of 7.0
Neutral
