Water Flashcards
Polar covalent bonds in water molecules result in hydrogen bonding. Four emergent properties of water contribute to Earth's suitability for life. Acidic and basic conditions affect living organisms
Polar Covalent Bonds
A covalent bond between atoms that differ in electronegativity. The shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive
Polar Molecule
A molecule (such as water) with an uneven distribution of charges in different regions of the molecule
Cohesion
The linking together of like molecules, often by hydrogen bonds
Adhesion
The clinging of one substance to another, such as water to plant cell walls by means of hydrogen bonds
Surface Tension
A measure of how difficult it is to to stretch or break the surface of a liquid. Water has a high one because of the hydrogen bonding of surface molecules
Kinetic Energy
The energy associated with the relative motion of objects. Moving matter can perform work by imparting motion to other matter
Thermal Energy
Kinetic energy due to the random motion of atoms and molecules; energy in its most random form
Temperature
A measure in degrees of the average kinetic energy (thermal energy) of the atoms and molecules in a body of matter
Heat
Thermal energy in transfer from one body of matter to another
Calorie (cal)
The amount of heat energy required to raise the temperature of 1g of water by 1*C. The Calorie (with a capital C), usually used to indicate the energy content of food, is a kilocalorie
Kilocalorie (kcal)
A thousand calories; the amount of heat energy required to raise the temperature of 1kg of water by 1*C
Joule (J)
A unit of energy: 1J=0.239cal; 1cal=4.184J
Specific Heat
The amount of heat that must be absorbed or lost for 1g of a substance to change its temperature by 1*C
Heat of Vaporization
The quantity of heat a liquid must absorb for 1g of it to be converted from the liquid to the gaseous state
Evaporative Cooling
The process in which the surface of an object becomes cooler during evaporation, a result of the molecules with the greatest kinetic energy changing from the liquid to the gaseous state
Solution
A liquid that is a homogeneous mixture of two or more substances
Solvant
The dissolving agent of a solution. Water is the most versatile one known
Solute
A substance that is dissolved in a solution
Aqueous Solution
A solution in which water is the solvant
Hydration Shell
The sphere of water molecules around a dissolved ion
Hydrophilic
Having an affinity for water
Hydrophobic
Having no affinity for water; tending to coalesce and form droplets in water
Molecular Mass
The sum of the masses of all the atoms in a molecule; sometimes called the molecular weight
Mole (mol)
The number of grams of a substance that equals its molecular or atomic mass in daltons; this contains Avogadro’s number of the molecules or atoms in question
