CHEMISTRY COMMUNITY

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they're synonymous

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there's a direct relationship so increasing temp should also increase K

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the area under the curve is the work by expansion

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weak acids have a pH that's closer to 7 (neutral)

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it didn't seem like a typo

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water dilutes the solution.Whether it increases or decreases cell potential depends on the problem

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n is the number of electrons that are transferred

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it helps you find the K when there are changes in temperature

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I do all the textbook problems

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reduction is in the cathode while oxidation occurs in the anode. Also, the cathode is typically on the right

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Gibbs free energy is the energy available to do work

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K is used when the reaction is at equilibrium and Q is used when it’s not

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When E is positive and delta G is negative, spontaneity is involved

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Zero means that the battery has died

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A salt bridge allows electrons to flow from one side to the other

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a negative delta G signifies the reaction is spontaneous.

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n is the number of moles of electrons being transferred

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adding an inert gas does not create a change

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salts have the ability to transfer electrons so a salt bridge allows the flow of electrons from one side to the other

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n=number of electrons transferred

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Typically if delta H is negative, delta S is positive and delta G is negative this indicates spontaneity

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There is no heat exchange

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Gibbs free energy is the energy available to do work. A negative delta G indicates spontaneity whereas positive delta G means it’s not spontaneous

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I also hope he curves it although I doubt he will. On the bright side, half the class will get a C or higher in the final grade I think

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Leo goes Ger [censored]
Losing electrons = oxidation
Gaining electrons= reduction

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when solving problems on the midterm, are we supposed to have final answers in J or kJ? or does it depend on the problem?

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when using PV=nRT is the temperature supposed to be celsius or kelvin?

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negative work means work is being done (expansion) whereas positive work signifies work is done on the system (compression)

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An isolated system has no contact with the outside environment (hence "isolated") whereas closed systems can still interact with the environment

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calorimeters keep a constant volume

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Since enthalpy is a state function, their values can be added/subtracted together

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There is no change in energy in an isolated system since there is no interaction with the outside environment

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PranaviKolla2B wrote:Can someone please define Hess's Law?

according to google, Hess' law "states that regardless of the multiple stages or steps of a reaction, the total enthalpy change for the reaction is the sum of all changes. This law is a manifestation that enthalpy is a state function."

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if they have the same number of moles on both sides they cancel out

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diatomic elements are steady and are found to be that way in nature so the enthalpy of formation is 0kj/mol

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the bigger the kb, the lower the pkb (log properties) which also means the stronger the base

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everything in the equation except for R is variable. R is a constant and you can use that accordingly with the information given in the problem

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K=273+c

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Entropy is a measure of disorder in the universe whereas enthalpy is how much heat is absorbed or released in a given reaction

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Two or more reactions can be added together

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Solids tend to have more “orderly” atoms since they’re stuck in their forms whereas gases have fast moving and “disorganized” atoms

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When doing the ice box, do we always subtract X from the reactants? Or is there a specific method to figure out which side we subtract X by?

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to find the pH use the concentration of an acid to find pOH use the concentration of a base. IF given pH you can simply subtract that from 14 to find the pOH

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Usually you should use the ICE table for weak acids/ bases since the strong ones fully ionize

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R is usually 0.082- it may also be on the formula sheet

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the concentration only affects the Kc not Kp

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Typically a reaction that forms bonds is exothermic whereas a bond breaking reaction is usually endothermic

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These are typically given on exams.

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There are no units since K is more so a ratio

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When products and reactants are in the same phase, the reaction is known as homogenous

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When dealing with equilibrium, the reactions are typically reversible meaning that it could be left to right or the other way around

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Both are calculated using the same formulas but Q is used anytime during the reaction whilst K is calculated with equilibrium concentration and values!

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105289321 wrote:Are LDF present in all molecules?

yes London Forces are present in all molecules

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I am confused as to how we should order the electron configurations. I recall the correct order being like 4s2 then 3d10. However, in the textbook and midterm solutions it shows them being 3s2 3p6 3d10 then 4s2 4p6 etc. Which is right??

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In most situations, pH ranges from 0-14

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water can act as both an acid and a base

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ammonia would be considered a weak base

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Lewis acids will donate electrons and Lewis bases will accept electrons

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an acid donates electrons, whereas a base accepts electrons

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As stated above, the sigma bonds have more of an overlap in the electron cloud between the atoms, thus making the bond stronger.

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Simply including the X and the E would suffice.

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yes I believe they are metals with d orbitals.

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first and foremost, place them in alphabetical order then find its charge

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cis molecules are polar whereas trans molecules are nonpolar

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hydrogen bonds occur when hydrogen bonds with the electronegative elements F, O, N

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resonance structures are lewis structures that are essentially all the same but have double/triple bonds at different locations

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they need to all add up and equal the overall charge

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Lone pairs are indeed regions of electron density as they alter the shapes of molecules

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double bonds are shorter since the bonds are stronger and pull them closer together

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the formal charge should be zero (or close to it) in order for the octet to be complete and create stability.

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ideally, the atoms want to be in their complete octet state where they are the most stable, thus each formal charge should be as close to zero as possible.

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isoelectronic refers to the situation in which there the number of electrons are equal

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noble gases have no electronegativity since they already have complete octets.

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fluorine is the most electronegative element; it may be helpful to remember that electronegativity increases as you go to the upper right of the periodic table.

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ionic bonds are characterized as a bond between a metal and a nonmetal, whereas covalent bonds are bonds between two nonmetals.

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the pi bond is much weaker than the sigma bond due to the differences in the way that they overlap. Therefore, the pi bond would break first.

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Having the knowledge of whether a bond is a sigma or a pi bond allows one to figure out the structure of the molecule

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The double bonds are much stronger than single bonds, therefore the pull is stronger making them shorter

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Electrons that are closer to the nucleus are subject to more pull from the positively charged nucleus.

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The amount of energy it takes to remove an electron from the ground state of a gaseous atom, molecule or ion. The first ionization energy is the energy needed to remove the first electron from an atom. the second ionization energy is the energy needed to remove the second one and so on.

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I think for the most part it would only go as far as kilograms, but in any case, if megagrams and gigagrams were necessary I think we would be provided a formula sheet to convert the numbers.

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The atomic radius is measured only in the group state of the element. A side note: atomic radius increases as you go from the left of the periodic table and down. Therefore, francium has the largest atomic radius out of all the elements.

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Electrons in the outer shell are further from the nucleus; therefore, they are less susceptible to the attractive forces from the nucleus pulling them in.

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constructive inference is is "constructive" in the sense that its crests are aligned with that of another waves, which does create a higher amplitude. On the other hand, destructive inference is when the waves are unaligned and creates a lower amplitude.

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The negative exponent brings the “s” down to the denominator, making it “per second”.

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Longer wavelength means shorter frequency, (inverse relationship) since the longer wavelength can pass through less cycles in a set amount of time compared to shorter wavelengths. Blue light has a shorter frequency so it’s wavelength would be longer.

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I think white light is in a sense a homogenous mixture of all the different wavelengths (thus colors) of light

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There is no difference; reactant and reagent are the same thing.

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Precision is how close together your results are to each other, whereas accuracy refers to how close to the known (correct) value the results are.

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