AP Chem 2012 questions and answers (1-6)
(A) BeCl2
(B) SO2
(C) N2
(D) O2
(E) F2
Is a polar molecule. The easiest way to figure out whether a molecule is polar or non polar is to use these two principles: for a molecule to be nonpolar the central atom is surrounded by the sea atoms and has no lone pairs. Therefore, F2, O2, N2 are nonpolar (since its the same atoms connected to each other). BeCl2 is also nonpolar since beryllium is connected to two chlorines and has no lone pairs. Therefore, SO2 is polar, because sulfur has lone pairs on it. Choice B
Is best represented by two or more resonance forms. Resonance forms are forms of the same molecule where electrons are moved and have a different location. Resonance forms can occur for SO2, since either oxygen could have a double bond. Choice B
Is the molecule in which the intramolecular forces are strongest. Intramolecular forces should not be confused with intermolecular forces. Intramolecular forces refer to the bonds between elements in a molecule. Since N2 has a triple bond, it has the strongest intramelcular forces, choice C
(A) Oxidation-reduction reaction (B) Brønsted-Lowry acid-base reaction
(C) Sublimation (D) Dehydration (E) Precipitation
Occurs when aqueous solutions of ammonia and vinegar are mixed. Ammonia is a weak base with the formula of NH3, and vinegar is a weak organic acid, CH3COOH. The reaction between a base and an acid is called Brønsted-Lowry acid-base reaction. Choice B
Occurs when Al(s) and CuCl2(aq) are mixed. Aluminum will undergo a single replacement reaction with Cu, resulting in AlCl3 product. This reaction is oxidation-reduction reaction since elements oxidation numbers change. Choice A
Occurs when solid sodium acetate, NaC2H3O2(s)is added to water. When solid sodium acetate is added to water, it will dissociate into its ions, Na+ and C2H3O2- (weakly basic). Since acetate is basic a Brønsted-Lowry acid-base reaction will occur with water. Choice B
To prepare for your chemistry test, speak to our amazing chemistry tutor today. Our tutors are located in Bethesda, MD, Washington DC and online. Please call 646-407-9078 to schedule your session.