Chapter 3: Water & The Fitness of the Environment Flashcards
What is a polar molecule?
A molecule (such as water) with opposite charges on different ends of the molecule.
What is cohesion?
Cohesion is the binding together of like molecules, often by hydrogen bonding.
What is adhesion?
Adhesion is the clinging of one substance to another.
What is surface tension?
Surface tension is a measure of how difficult it is to stretch or break the surface of a liquid (e.g., water has a high surface tension because of the hydrogen bonding of surface molecule).
What is kinetic energy?
Kinetic energy is the energy associated with the relative motion of objects. Moving matter can perform work by imparting motion to other matter.
What is heat?
Heat is the total amount of kinetic energy due to the random motion of atoms or moelcules in a body of matter (also called thermal energy). Heat is energy in its most random form.*Please note–For a given body of matter, heat depends in part on the matter’s volume because it is a measure of the matter’s total kinetic energy.
What is temperature?
Temperature is a measure of the heat intensity in degrees that represents the average kinetic energy of the molecules, regardless of volume.
What is a joule (J)?
A joule (J) is a unit of energy: 1 J = 0.239 cal; 1 cal = 4.184 J.
What is a calorie (cal)?
A calorie is the amount of heat energy required to raise the temperature of 1 g of water by 1 degree of Celsius; also the amount of heat energy that 1 g of water releases when it cools by 1 gram of Celsius. The Calorie (with a capital C), usually used to indicate the energy content of food, is a kilocalorie.
What is a kilocalorie (kcal)?
A kilocalorie is a thousand calories; the amount of heat energy required to raise the temperature of 1 kg of water by 1 degree of Celsius.
What is specific heat?
The specific heat of a substance is defined as the amount of heat that must be absorbed or lost for 1 g of that substance to change its temperature by 1 degree of Celsius. (specific heat of water is 1 calorie per gram per degree of Celsius)
What is the heat of vaporization?
The heat of vaporization is the quantity of heat a liquid must absorb for 1 g of it to be converted from the liquid to the gaseous state (e.g., to evaporate 1 g of water at 25 degrees Celsius, about 580 cal of heat is needed).
What is evaporative cooling?
Evaporative cooling is the process in which the surface of an object becomes cooler during evaporation, owing to a change of the molecules with the greatest kinetic energy from the liquid to the gaseous state.
What is a solution?
A solution is a liquid that is a homogeneous mixture of two or more substances.
What is a solvent?
A solvent is the dissolving agent of a solution. Water is the most versatile solvent known.
