ETS Major Field Test – Chemistry Latest Update with Complete Solutions

ETS Major Field Test – Chemistry Latest Update with Complete Solutions what are isomers isomers are two compounds with the same molecular formula that are different What are the three types of isomers? 1. Structural (constitutional) isomers 2. Stereoisomers (two types) - enantiomers and diasteromers 3. Geometric isomers (also known as cis and trans isomers) what is a structural (constitutional) isomer? different bonding arrangement of atoms. atoms are bonded together in a different sequence what is a stereoisomer? what are the two types of stereoisomers? stereoisomers: atoms are bonded together in the same sequence, but have different 3-D arrangement in space enantiomers: non-superimposable mirror images diasteromers: stereoisomers that are not enantiomers: not superimposable and not mirror images what is a chiral atom? an atom that has four different groups attached to it If a chiral atoms is in the "R" configuration, in what direction does the arc go? if a chiral atom is in the "S" configuration, in what direction does the arc go? -R configuration - clockwise -S configuration - counterclockwise how many chiral centers does a diastereomer need to have? at least 2 how does molecular weight relate to water-solubility? the larger the molecular weight, the lower the water solubility -How does the presence of hydrogen-bonding change the water-solubility? -What can hydrogen-bond with water? -increases water solubility -alcohols, amines, C=O, ethers, and F What shape of a molecule can make a substance less water-soluble and why The more linear, the less water soluble, due to a greater non-polar surface area than a branched molecule of the same molecular weight How does molecular weight relate to boiling point? the larger the molecular weight, the higher the boiling point. what shape of a molecule can make a molecule have a higher boiling point and why? The more linear, the higher boiling point, due to a greater surface area than a branched molecule of the same molecular weight.The more surface area, the more chances for van der Waals attractions. How does the presence of hydrogen-bonding change the boiling point? The presence of hydrogen-bonding increases boiling point dramatically.Alcohols, 1* and 2* amines and amides, and carboxylic acids all hydrogen-bond with other molecules of themselves.Dipole-dipole attractions between C=O's increase boiling point to a lesser extent. What does Nuclear Magnetic Resonance (NMR) Spectrometry tell us? NMR tells us how many different types of hydrogens or carbons there are in a compound What does the position of the peak in NMR tell us