How good is a 39/50 on the 2014 multiple choice? Would that put me in a good position for a 5?
thats very good
39/50 = 78% so that would be a good position for a 5 assuming you get above a 60% on the FRQ
@APScholar18 - That’s just applying M1V1=M2V2. You have a 0.173 M base and add 20.52 mL of it to 25.00 mL of acid. Just multiply the base numbers and divide by the acid volume (don’t forget to change to L) to find the molarity of the acid.
@glasshours when in titration calcs do you divide by the total volume?
@APScholar18 - When you have to recalculate the number of moles. For example, in a weak acid/weak base titration before the equivalence point (assuming that the volume of base added is significant), some of the base added consumes the H+ ions of the acid. You’d have to calculate the initial number of moles of acid, subtract the number of moles of base added, then divide by the new total volume to find the new H+ ion concentration. Usually, they’ll ask you to calculate pH from that.
since we can’t say london dispersion is based on mass, are we supposed to say its based on the number of electrons or what>
Are there deductions for wrong answers? Also just to confirm the Ti-nspire CAS is an allowed calculator, right?
@mathman97 you have to say that increase mass results in increased polarizability because the electrons are farther from the positive nucleus and therefore have less effective nuclear charge. They’re easier to distort. This results in greater polarizability and that’s directly proportional to london dispersion forces. So the pattern is correct looking at molar mass, just the specific reason is this.
@Mathman97 - Talk about the constant motion of electrons creating a temporary dipole. The larger the molecule, the less tightly valence electrons are held and the more easily they can form LDFs. Larger molecules also have larger electron clouds, and are therefore more easily distorted/have greater polarizability. College Board seems to like that last phrase a lot, haha
@SnowCookie no deductions for wrong answers. I’m not sure but there’s a list on the collegeboard website. I think anything without QUERTY keyboard is fine
^It depends on your frq score, but to be safe, maybe 40/50+.
if hydrogen bonding is so strong, how come hcooh, a molecule with h bonding dissolves easily because of its hydrogen bond?
anyone know a good matchup for MC and FRQ to get a 4?
I can get around 50% atleast on the FRQ (depending on the type of questions asked) and around a 60-70% on MC but idk the distrib. range for a 4 exactly so
Could someone message me the multiple choice questions from 2014? or have a link where i can access them?? much appreciated!!
In galvanic cell if you decreased the Molarity of the Cathode side what would happen to E?
i dont think e changes based on molarity
anyone know #29 on the 2014 test?
@Mathman97
you are getting confused about H-bonding…
substances that are really good at dissolving in water are so because they are either ionic compounds (ion-dipole IMF) , polar (dipole-dipole), or exhibit hydrogen bonding. With formic acid (hooch), the lone pairs on the O allow for water to easily hydrogen bond with those lone pairs along with the fact that the H on the other O can hydrogen bond to the lone pairs on the water molecule. This means that formic acid EASILY dissolves in water because of both of these cases for H-bonding. This is also why some alcohols, like ethanol, also dissolve because they have H-bonding on the OH. Dissolving doesn’t always mean breaking ionic bonds between ionic compounds… sugar dissolves in water but those covalent bonds sure aren’t breaking.
so you need a 72 on the FRQs and a 72 on the MC or am I scoring it wrong???