Unit 7-9? Flashcards
Kinetic energy is associated with _____.
Motion
Potential energy is associated with ____ or _____.
Position or composition.
Chemical energy is a form of _____ energy.
Potential
Thermal energy is a form of _____ energy.
Kinetic
Chemical energy is associated with:
Relative positions of electrons and nuclei in atoms and molecules
Heat is the _____ of thermal energy.
Transfer
Breaking bonds _____ energy.
Consumes or absorbs (+)
Forming bonds _____ energy.
Releases (-)
Heat is absorbed (+ delta H) in ______ reactions.
Endothermic
Heat is released (- Delta H) in _____ reactions.
Exothermic
Bonds broken in reactants are stronger than bonds formed in products. What is the reaction?
Endothermic
Products are higher in energy than reactants. What is the reaction?
Endothermic
Bonds formed in products are stronger than bonds broken in reactants. What is the reaction?
Exothermic
Products lower in energy than reactants. What is the reaction?
Exothermic
Delta H reaction is the difference between energy needed to ______ in the reactants and the energy needed to _____ in the products.
Break bonds, form bonds.
Increase [_____] leads to an increase in the _____ of _____ leads to increase _____.
Reactants, number of collisions, reaction rate.
Increasing temperature drives a chemical rxn by increasing the _____ of each molecule, leading to more _____ _____, and increasing the overall _____ _____.
Energy, successful collisions, reaction rate.
Catalysts effects the _____, and not the _____.
Reaction rate (fast or slow), not delta H.
Catalysts do not appear in the _____.
Product.
Catalysts speed up the rxn rate by _____ the activation energy.
Lowering
Equilibrium is the point in which the rate of the forward reaction ______ the rate of the reverse reaction.
Equals
Molarity ( __ ) equals x/x
Capitol M, moles / liters.
K = [ _____ ] / [ _____ ]
K (equilibrium constant) = concentration of products / concentration of reactants
K>1, equilibrium favors _____.
Products
K<1, equilibrium favors _____.
Reactants
K~1, _____ and _____ are present.
Reactants and products
Le Chatelier’s Principle basically states that:
If a chemical system is stressed, it will react in the direction that relieves the stress. It finds balance!
Delta H is always written for the _____ direction.
Forward
Gasses have a(n) _____ volume and a(n) _____ shape.
Indefinite, indefinite.
Liquids have a(n) _____ volume and a(n) _____ shape.
Definite, indefinite.
Solids have a(n) _____ volume and a(n) _____ shape.
Definite, definite.
Unit of pressure:
Atmospheres = ( _____ )
atm
Unit of pressure:
psi =
Pounds per square inch
Unit of pressure:
(Pa) =
Pascals
How many mmHg are in one atm?
760.
How many torr in one atm?
760.
STP stands for:
Standard temperature (273 K), and pressure (1 atm)
At STP, the molar volume of any ideal gas is _____ Liters.
22.4
A rxn with a lower activation energy is (more/less) likely to occur than a rxn with a higher activation energy.
More likely
A higher activation energy is typically associated with (slower/faster) rxn rates.
Slower, because fewer particles has sufficient energy to overcome the E of a (activation energy) and form products.
Catalysts (are/ are not) consumed in an overall reaction.
Are not.
1 calorie = (x) Joules
4.184 joules
1 Pa = x PSI
1.45 x 10^-4
What affects rate of chem rxn?
Temperature, concentration of reactants, and presence of a catalyst.
Potential energy is stored in _____ or _____ bonds.
Ionic or covalent
Bond dissociation energies are (+-) and bond formation energies are (+-).
Positive, negative.
The higher + delta H, the more energy required to _____ the bond. Decreasing dissociation energy as you move _____ a group, and as atomic size _____.
Break. Down. Increases.
Electrostatic interactions exist WITHIN _____ compounds.
Ionic
INTRAmolecular forces) are:
Forces that hold molecules together (form bonds).
INTERmolecular forces (IMF) are:
Attractive forces between molecules or ions that hold them near each other.
What is the weakest force of all three intrOmolecular forces? What kind of line is used to represent these forces?
IntERmolecular forces, - - - - - line.
List the three types of intERmolecular interactions between molecules?
London dispersion forces, dipole-dipole, and hydrogen bonding.
What is a temporary dipole?
A momentary change in the e- density of a molecule. They can shift back and forth from non-polar to polar. & they create temporary dipoles in neighboring molecules.
All covalent compounds have what type of intermolecular interactions?
London dispersion forces.
Non-polar covalent compounds have only what type of intermolecular interactions?
London dispersion forces
The larger the (mass of a) molecule, the _____ the forces between two molecules.
Stronger
Dipole-dipole interactions are:
Attractive forces between permanent dipoles of two POLAR molecules.
Hydrogen bonding occurs when ___ atom is bound to: ___, ___, or ___. And can be broken apart using _____ means.
H bound to O,N, or F. Physical.
Boiling point is defined as:
The temperature in which a liquid becomes a gas.
Melting point is defined as:
The temperature in which a solid becomes a liquid.
The strength of the intermolecular force is proportionally related to:
Boiling point, melting point, and surface tension.
The strength of the intermolecular force is inversely related to:
Vapor pressure.
Surface tension is defined as:
The measure of resistance of a liquid spread out.
Sublimation, vaporization, and melting, are all processes in which energy is _____.
Absorbed.
Deposition, condensation, and freezing are processes in which energy is _____.
Released
Sublimation is when you go from a _____ to a _____ and skip the _____ phase altogether.
Solid to a gas and skip the liquid phase. (Dependent on atm pressure)
What is not included in the K expression?
Pure solids and liquids because they have constant concentrations.
_____molecular forces/attractions influence the chemical properties of a substance, and _____molecular forces/attractions influence the physical properties of a substance.
Intramolecular forces, intermolecular attractions.
Vaporization is the phase of ____ becoming _____.
Liquid becoming a gas
Condensation is the phase of _____ becoming _____.
Gas to a liquid
Sublimation is the phase of _____ becoming _____.
Solid to a gas
Deposition is the phase of _____ becoming _____.
Gas to solid
Any time particles are close together and need to be pulled apart, energy needs to be _____.
Absorbed
Any time particles are going from less compact to more compact, energy will be _____.
Released
What is solute?
The substance present in smaller amount.
What is solvent?
Substance present in larger amount
What is solubility?
Max amount of solute that dissolves in a given amount of solvent under a given set of conditions
List the three mixtures in order of particle size (smallest to largest)
Solution, collid, and suspension.
When a solute is added, vapor pressure _____.
Decreases
When a solute is added, the freezing point _____.
Decreases
When a solute is added, the boiling point _____.
Increases
Freezing-point depression is directly proportional to the _____ per formula unit.
Ions
