MCAT General Chemistry Questions & Answers

MCAT General Chemistry Questions & Answers "fawn-cull-brisch" - CORRECT ANSWER - F O N Cl Br I S C H... These are the electronegative atoms in descending order starting from most electronegative; bonds between H and anything before C will give H a 1+ oxidation state 1amu= - CORRECT ANSWER - Approximately 1 proton or 1 neutron. Hence 1 C atom is 12 amu Acidity - CORRECT ANSWER - acidity increases from left to right across a period and increases down a group or family in the periodic table Alpha particle - CORRECT ANSWER - Helium-4 atom (2neutrons and 2protons) Atomic and Ionic Radius - CORRECT ANSWER - from left to right in a period atomic radius *decreases* and from top down in a group the atomic radius *increases* due to the shielding effect Beta - decay - CORRECT ANSWER - Coverts neutron to proton and a B- particle (electron) which is ejected Beta + decay - CORRECT ANSWER - Conversion of proton to neutron and emission of positron (anti-electron) Bond Dissociation Energy - CORRECT ANSWER - the energy required to break a bond homolytically In *Homolytic Bond Cleavage* one electron of the bond being broken goes to each fragment of the molecule ...in this process two *radicals* form In *Heterolytic Bond Cleavage* (aka dissociation) both electrons of the electron pair that make up the bond end up on the same atom, forming a *cation* and *anion* ***Bond length and BDE comparisons should only be made for similar C-C bonds I.E. C-C and C=C bonds (only carbon -carbon bonds and other carbon-carbon bonds) Bond Length - CORRECT ANSWER - the distance between two nuclei that are bonded to one another Define enthalpy - CORRECT ANSWER - is a measure of the heat energy that is released or absorbed when bonds are broken and formed during a reaction that's run at constant pressure. Symbol used is H.