Water Flashcards
When does a polar covalent bond form?
When atoms join in a bond but do not have equal electronegativity. One desires electrons more resulting a partial negative charge and the other recieves a partial positive charge.
Polar molecule
Molecule that contains unequal sharing of electrons
Hydrogen bond
A partial positive and a partial negative charge come together to join two polar molecules. weaker than both ionic and covalent bonds.
Important properties of water include…
1) Cohesion (attraction of one water molecule to another) and adhesion (attachment to anything other than water)
2) Temperature moderation (absorbs heat from warm air and releases it to cool)
Heat
Measure of the toal kinetic energy of a body. (Volume dependant)
Temperature
Average kinetic energy of all molecules (volume independant)
Calorie
Amount of energy needed to raise the temperature of 1g of water by 1 degree celcius.
Specific heat
The amount of energy need to raise the temperature of 1g of substance by 1 degree celcius.
Why does water have a much higher heat capacity compared to other substances?
Hydrogen bonding (before the heat can be absorbed hydrogen bonds must be broken)
Evaporation of a substance is a form of what?
Temperature moderation (the hotter molecules are released and the substance becomes cooler because of this loss)
Water is an excellent…
Solvant (it can dissolve many ionic compounds)
Why does ice float in liquid water?
Each water molecule forms 4 hydrogen bonds resulting in a crystal lattice. Since liquid water is continuously breaking and reforming hydrogen bonds water that is frozen is a much more stable structure and therfore less dense.
Solvant
Dissolving agent (usually water)
Solute
Dissolved substance
Solution
Combination of both a solvant and a solute to form a homogenous mixture. (aqueous solutions are those in which water is the solvant)
