Chem final

What increases reaction rate?

increasing concentration, temperature

How do catalysts affect reaction rates?

increase the rate of both the forward and reverse reactions

What is rate of a reaction?

measured using the concentration change for a reactant or a product over time

What is instantaneous rate?

the slope of the curve at one point in time

What is initial rate?

the instantaneous rate at time zero

What is rate law?

which shows the relationship between rate and concentration for all reactants

What value of k makes a fast reaction?

reaction with k=10⁹ or higher

What value of k makes a slow reaction?

reaction with k=10 or lower

What is the collision model?

molecules must collide to react, more collisions is more reactions, molecules can often collide without forming products

What is activation energy?

the minimum energy needed for a reaction to take place

What is the rate determining step

slowest step

What are enzymes?

they are biological catalyats, they have a region where the reactants attach, it is called the active site and the reactants are called substrates

What happens if Q is less than K?

the forward reaction proceeds to form more products

What happens if Q = K?

the reaction is at an equilibrium

What happens if Q is greater than K?

the reverse reaction proceeds to form more reactants

What happens when endothermic reactions increase and decrease temperature?

shifts right, shifts left

What happens when exothermic reactions increase and decrease temperature?

shifts left, shifts right

How do you describe endothermic reactions?

heat acts like a reactant, adding heat drives a reaction towards products

How do you describe exothermic reactions?

heat acts like a product, adding heat drives a reaction toward reactants

What is an arrhenius acid?

a substance that when dissolved in water, increases the concentration of H ions

What is a arrhenius base?

a substance that when dissolved in water, increases the concentration of OH ions

What is a bronsted lowry acid?

a species that donates H ions

What is a bronsted lowry base?

a species that accepts H ions

What happens if h30 is greater than OH?

the solution is acidic

What happens of H30 is less than OH?

the solution is basic

What happens when pH decreases?

the acidity increases

What are strong acids also called?

strong electrolytes

What are the most common strong bases?

ionic hydroxides of the alkali metals or the heavier alkaline earth metals

What happens if Ka is less than 1?

the acid is completely ionized and the acid is a strong acid

What are polyprotic acids?

have more than one ionizable proton

What happens if Kb increases?

the base gets stronger

What is a lewis acid?

an electron pair acceptor

What is a lewis base?

electron pair donor

What is the common ion effect?

the dissociation of a weak electrolyte is decreased by the addition of a strong electrolyte that has an ion in common with the weak electrolyte

What is a buffer?

a solution that resists drastic change in pH upon addition of small amounts of strong acid or strong base

What increases the buffer capacity?

the greater the concentrations of the conjugate acid-base pair

What is a pH range of a buffer?

within 1 pH unit of the pKa of the buffering agent.

What is molar solubility?

the number of moles of solute that dissolve to form a liter of saturated solution

What is a quantitative analysis?

designed to determine how much metal ion is present

What is a qualitative analysis?

designed to detect the presence of metal ions

What is a solvent?

is the component present in the largest amount

What process is mixing gases?

spontaneous

What is enthalpy?

total heat content, delta H

What is entropy

measure of disorder, delta S

What is solvation?

an interation between a solvent and its dissolved molecules, aka a solute

What is hydration?

if water is the solvent interacting with the solutes

What determines is a solution will form?

if the enthalpy is negative

What causes a solution not to form?

if the enthalpy is too positive, endothermic

What is crystallization?

when a solution breaks down to a solute and a solvent

What indicates a saturated solution?

if crystallization and dissolution are in equilibrium with an undissolved solute

What is solubility?

the amount of solute required to form a saturated solution at a specified temperature

What indicates a unsaturated solution?

a solution with a concentration of dissolved solute that is less than the solubility is said to be unsaturated

What factors create a low solubility?

hydrocarbons, and alot of C atoms

What is henry’s law?

the solubility of a gas in a liquid solvent is directly proportional to the partial pressure of the gas above the solution.

What increases solubility?

increasing temperature, except when gas in water

What is osmotic pressure?

pressure required to prevent osmosis

What is isotonic?

when two solutions have the same osmotic pressure

What are hypotonic solutions?

they have a lower osmotic pressure and have a more concentrated solution

What are hypertonic solutions?

they have a higher osmotic pressure and have a lower concentrated solution

What are colloidal dispersions?

suspensions in which the suspended particles are larger than molecules but too small to separate of the suspension due to gravity

What do boiling points reflect?

intermolecular force strength

What to melting points reflect?

the strength of attractive forces

What is the weakest intermolecular force?

dispersion forces

What indicates hydrogen bonding?

When H is bonded to F,O,N

What indicates a strong molecular force?

a greater/increasing molecular polarity

What are the strongest intermolecular forces?

molecules capable of hydrogen bonding or ionic bonding

What does viscosity depend on?

the attractive forces between molecules, the tendency of molecules to become entangles, the temperature

What is surface temperature?

the amount of energy required to increase the surface area of a liquid by a unit amount

What indicates a stronger surface temperature?

stronger intermolecular forces like hydrogen bonding or ionic bonding

What are cohesive forces?

bind molecules to one another

What are adhesive forces?

bind molecules to the surface

What is sublimation?

solid to gas

What is deposition?

gas to solid

What is critical pressure?

the pressure required for liquefaction at this critical temperature

What is vapor pressure?

when pressure created by its vapor when both the vapor and liquid are at dynamic equilibrium