Exam 1 Flashcards
The O-H bonds in water are polar due to the high electronegativity of hydrogen.
False.
Water is a polar molecule due to its bent geometry.
True.
In the liquid state, each water molecule has the potential to form hydrogen bonds with four other water molecules.
True.
Compounds that dissolve readily in water are termed hydrophilic and include electrolytes as well as nonelectrolytes.
True.
Electrolytes (e.g. NaCl) are polar and dissociate into anions & cations, each surrounded by water molecules that form a solvation sphere. Nonelectrolytes also become hydrated by water due to hydrogen bond formation between water and polar –OH groups.
The osmotic pressure of an aqueous 0.001 M starch solution is greater than that of an aqueous 0.001 M glucose solution.
False.
Polar molecules can induce polarity in nonpolar molecules.
True.
An aqueous solution of pH 3.0 contains H2O, H+, and OH-.
True.
An acid that dissociates to the extent of 88% in water would be termed a strong acid.
False.
An acid is weak if it dissociates less than 100% in water.
A solution that contains 0.05 mol of lactic acid and 0.05 mol of potassium lactate per liter of solution has a pH of 3.86.
True.
The major buffer system of the blood is the bicarbonate-carbonic acid buffer system.
True.
The shell of water molecules that surrounds a dissolved ion or molecule is called a hydrosphere.
False.
It is called a solvation sphere.
Although they operate over similar distances, hydrogen bonds are much stronger than van der Waals forces.
True.
In a buffer system, increasing the concentration of the conjugate base relative to that of the conjugate acid increases pH.
True.
Hydrophobic interactions explain why the olive oil in an open bottle does not readily evaporate.
False.
Hydrophobic interactions explain why hydrophobic molecules aggregate when placed in an aqueous environment.
____ is the tendency of an atom to attract to itself the shared electrons is a covalent bond.
Electronegativity
. ____ agents are certain ions and molecules that are poorly solvated in water and enhance the solubility of nonpolar compounds by disordering the water molecules.
Chaotropic
____ molecules contain both hydrophobic and hydrophilic groups.
Amphipathic
Soap molecules dissolved in water tend to form aggregates called ____.
Micelles
A shell of water molecules that forms around ions as they become dissolved is called a/an ____.
Solvation sphere
Attractive forces between molecules, collectively called ____, can occur due to dipole-dipole attractions, ion-dipole attractions, and interactions between two nonpolar atoms or molecules that result in transiently induced dipoles, which are known as London dispersion forces.
Van der waals
The unit(s) of Kw, the ion-product constant of water, is/are ____.
M2
An acid or base that dissociates less than 100% in water is described as being ____.
weak
The unit(s) of Ka, the dissociation constant for a weak acid, is/are ____.
M
A solution that contains equal or nearly equal quantities of a weak acid and its conjugate base is called a/an ____.
buffer