Test 1
暂无描述。系统推荐的高质量记忆内容，适合每天坚持背诵学习。
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What is the electronegativity difference of an ionic bond?
Greater than 1.9
What is the electronegativity difference of a polar covalent bond?
0.5-1.9
What is the electronegativity difference of a nonpolar covalent bond?
Less than 0.5
How do you determine formal charge?
Valence electrons on periodic table minus # of bonds and lone electrons in molecule
How do the melting points and boiling points of ionic substances compare to covalent substances?
Ionic substances have high melting and boiling points
what determines a molecular substances physical properties?
types and strengths of intermolecular forces
what are three types of intermolecular forces?
dispersion forces dipole-dipole forces hydrogen bonding forces
what is a protic solvent?
a solvent that donates a hydrogen bond
what is an aprotic solvent?
a solvent that cannot serve as a hydrogen-bond donor
what is a polar solvent?
a solvent with a dielectric constant of 15 or greater
what is a nonpolar solvent?
a solvent with a dielectric constant less than 15
what is a dielectric constant?
a measure of a solvent’s ability to insulate opposite charges from one another
what two factors determine if a substance is a good solvent?
• separate solute particles (same type and strength of intermolecular forces) • keep them separated (if ionic or polar molecules make up solute, requires a large dielectric constant)
what is a bronsted-lowry acid
substance that donates a proton
what is a bronsted-lowry base?
accepts a proton
what is needs to be stable for a substance to be an acid?
anion (conjugate base)
what 5 factors stabilize the anion of an acid?
• more electronegative • larger radius • delocalization with resonance • delocalization through electron withdrawing • more s character (% of hybrid orbital that s constitutes)
what is the inductive effect?
the polarization of the electron density of a covalent bond by the electronegativity of a nearby atom
define the acid dissociation constant
K = [A-][H3O+]/HA
How do you calculate PKeq?
pKha - PKbh+ acid minus conjugate acid, according to equation given
what must be true about PKeq for a reaction to be favorable?
it must be negative
what is the general formula for an alkane?
CnH2n+2
what are constitutional isomers?
compounds with the same molecular formula but a different connectivity of their atoms
What is a bicycloalkane?
an alkane containing two rings that share two carbons