Smartbook chapter 2
Molecules that are more polar tend to have which of the following characteristics?
A higher heat of vaporization A higher specific heat
An atom is composed of a central nucleus which is surrounded by which orbiting particles?
Electrons
The chemical behavior of an atom is determined by the number and configuration of its
Electrons
In living systems, which of the following catalyze almost every chemical reaction necessary for life?
Enzymes
When 1 g of sugar is dissolved in 500 mL of water, the sugar is called the________and water is called the _________.
Field 1: solute Field 2: solvent
When 1 g of fructose is dissolved in 500 mL of water,___________ is the solvent and_______ is the solute.
Field 1: water Field 2: fructose or sugar
The amount of energy required to change 1 g of a substance from a liquid to a gas is called which of the following?
Heat of vaporization
What is the temperature of a substance a measure of?
How fast its molecules are moving
What does it mean when we say water is adhesive?
It is attracted to other polar molecules and ions.
A group of atoms held together by chemical bonds in a stable association is called which of the following? Multiple choice question.
Molecule
Chemical reactions that involve a transfer of electrons from one atom to another are called _______reactions.
Redox
Which of the following is the definition of the heat of vaporization of water?
The amount of energy needed to change 1 g of water from a liquid to a gas
The___________ of a substance is a measure of how rapidly its individual molecules are moving.
temperature
The pH of a solution is defined as _____.
the negative logarithm of the hydrogen ion concentration in the solution
A hydrogen ion, formed during the dissociation of water, has a charge of which of the following?
+1
What is the charge of a hydroxide ion?
-1
Molecules that are more polar tend to have which of the following characteristics?
-A higher specific heat -A higher heat of vaporization
Arrange the following states of water in order from most dense to least dense (start with most dense at the top).
-Liquid -Solid -Gas
A(n) __________ is a substance or a mixture of substances that act to resist changes in pH.
Buffer
Because polar water molecules attract each other, water is said to be ________
Cohesive
Water consists of one oxygen atom joined to two hydrogen atoms by what type of bonds?
Covalent
Consider a large protein molecule that has some parts that are highly hydrophobic. When placed in a water solution, the protein folds in a globular shape, such that all the hydrophobic portions are inside the molecules, away from water. This is an example of which of the following?
Hydrophobic exclusion
Which property of water strongly affects the overall shape of many biological molecules, such as protein, and DNA?
Hydrophobic exclusion
Where are the valence electrons of an atom found?
In the outermost energy level only
The atoms in NaCl are held together by what type of bond?
Ionic
_____can be defined as any substance that has mass and occupies space
Matter
Water has several properties important to life: high specific heat, high heat of vaporization, lower density in solid form (ice), ability to act as a solvent and to organize nonpolar molecules. What explains these properties of water?
The polar nature of water molecules
When NaCl is formed, ______.
a sodium atom loses an electron, while a chlorine atom gains an electron
Redox reactions involve a transfer of _________ from one atom to another.
electrons
An living organisms, almost all chemical reactions are catalyzed by protein catalysts called ___________.
enzymes
If two atoms are joined by a polar covalent bond, the shared electrons will tend to stay closer to the atom with______.
higher electronegativity
Solid water is ________dense than liquid water.
less
Solid water is_______ dense than liquid water.
less
Anything that has mass and occupies space is defined as ______.
matter
A(n)_________ is made of two or more atoms held together by chemical bonds in a stable association. The atoms may or may not belong to the same element.
molecule
Generally speaking, an atom is made of a central _________which is surrounded by orbiting_________.
neuclus, electrons
Substances or mixtures of substances known as buffers, act in living things to resist changes in ______.
pH
The negative logarithm of the hydrogen ion concentration of a solution is known as its _____.
pH
If two atoms are joined by a polar covalent bond, the atom with the lower electronegativity will have a partial_________charge.
positive
The number and configuration of electrons determines an element's______.
chemical properties
Water consists of one oxygen atom joined to two hydrogen atoms by two single, polar ___________bonds.
covalent
The attraction of water to other polar substances is called ________.
Adhesion
Water is cohesive because water molecules are______.
attracted to each other
Valence electrons and their interactions determine the_____________properties of an element.
chemical
