Kaplan FL 1 Gen Chem (Updated) Flashcards
Find the equilibrium constant expression
pure solids and pure liquids are NOT part of equilibrium expression– only nitric oxide and water vapor
How do we find the max amount of a H20 produced if we have 2 moles of aluminum powder and 3 moles of ammonium perchlorate?
Right now we have 3 mol Al and 3 ammonium perchlorate which makes 6 moles of H20 (balanced eq)
- H20 is on the product side
- check that the equation is balanced (3 Al + 3 ammonium perchlorate => 6 H20)
- find a limiting reagent
Al has the fewer moles at start than the other reactant ammonium perchlorate - to find the number moles of product
limiting reagent x (6 mol H20/3 mol Al) = 4 mol H20
MAKES 4 mol H20!!
What is the limting reagent and what is it used for in problems?
limting reagent is the reagent that is consumed completely. If there is no more, reaction cannot proceed (it limits the reaction).
the excess reagent is the reactant that could keep reacting if the other has not been consumed
to figure out the amount of product find the limiting reagent and multiply by (mols of other products) / (mols of other reactants)
Which of the following shifts a equilibrium to the right
decrease pressure
increase pressure
decrease reactant
increase product
decrease in pressure shifts to the side with MORE moles of gas…. in this case its the PRODUCTS
(increasing P would shift to the LESS moles side… in this case the reactants)
(only INCR reactants or DEC products will shift to products)
introducing a catalyst would do what to NO at equilibrium?
it remains the same
pos of reaction has to do with diff in free energy of products and reactants
catalysts speed up but dont affect energies of products or reactants and cant affect concentrations of product and reactants
If the forward reaction is spontaneous under standard conditions (delta G neg) then the reverse reaction must be ________ in standard conditions and have a ____ delta G
If the forward reaction is spontaneous under standard conditions (delta G neg) then the reverse reaction must be ____non spontaneous____ in standard conditions and have a _pos___ delta G
How is 1,3 BP + ADP –> 3PG + ATP spontaneous in glycolysis and also runs in the reverse in gluconeogenesis? In terms of delta G how can the cell achieve a spontaneous reverse reaction
ratio of products to reactants must be altered so ln(Q) is positive for forward reaction
incr products;reactants will create POS ln(Q) and pos G for forward reaction which will make a spontaneous reverse reaction with neg G
–> same as increasing the concentrations of the substrates. we can do this by running it at non standard conditions to allow for pos G in forward and neg spontaneous G in reverse. This allows a shift between glycolysis and gluconeogenesis
first find the equilibrium expression for dissolution of calcium phosphate
Ca3(PO4)2 which makes 3 moles Ca2+ and 2 moles phosphate ions for each x moles of calcium phosphate
set Ca2+ to 3x with exponent 3 for # of moles
set PO4 to 2x with exponent 2 for # of moles
isoelectric point
The isoelectric point (pI) of a protein is defined as the pH at which the net charge of a protein molecule is zero
if the isolectric point is 9.7 what pHs will protenate and deprotenante the molecule?
and which pH will fragment move toward cathode?
molecule is protenated at pH below 9.7 and pos charged
molecule is deprotenanted at pH above 9.7 and neg charged
at ph <9.7 like 4.3 it will be protenated and move to the Cathode which likes POS charges
a double bond indicates what hybridization
sp2
triple bonds have what hybridization
sp
single bonds have what hybridization
sp3 hybridized
tertiary structure involves
- peptide bonds between amine and carboxyl groups
- hydrogen bonds between amine and carboxyl groups
- hydrogen bonds between R groups
- peptide bonds between R groups
choose 1
hydrogen bonds between R groups
tertiary structre - interactions between R groups (ionic bonds, covalent bonds, H bonds)
if X +2+ has 18 electrons, what is the atomic number
atomic # = # protons
if ion charge is +2, it has 2 more protons than electrons
if ion has 18 electrons then it must have 18+2 = protons
(if it were -2 it would mean 2 less protons than electrons)
what is ka and pka? how are Ka and pkA related?
Ka is the acid dissociation constant.
pKa is simply the -log of this constant. S
similarly, Kb is the base dissociation constant, while pKb is the -log of the constant.
The acid and base dissociation constants are usually expressed in terms of moles per liter (mol/L).
