Quiz 2 - Physical Properties of Organic Solvents Flashcards
What is the most common solvent?
Water
Water _____ dissolve many different compounds and is found in _____ _______ of solutions.
Can; all kinds
T/F If a solvent isn’t given in a solution it is assumed to be water
True
The behavior of organic solvents is determined by their…
Molecular structures
Define Water-Miscible
An organic solvent that will dissolve in water, they will mix
The more similar the intermolecular forces between water molecules and a solvent, the _______ likely it is that the solvent will dissolve in water.
MORE
Molecules that are characterized as having weak intermolecular forces have _______ densities.
Low
Molecules with heavier atoms will have ______________ densities.
Higher
What are some examples of heavier atom molecules?
Chlorine or Bromine
Organic solvents that evaporate easily and boil at low temperatures have _______ vapor pressures.
High
The boiling point of a solvent is determined by…
- The size and shape/symmetry of its old holes
- Strength of its intermolecular forces
Solvents with low boiling points evaporate ____________.
Easily
Solvents with low boiling points ______ be removed easily by mild heating.
Can
Boiling points can also be affected by the ________________ ______________ at which the measurement is taken.
Atmospheric pressure
If atmospheric pressure is low, the measured boiling point will be ________.
Low
The ability of a solvent to dissolve other compounds depends on…
How similar the solvent’s polarity is to the compound (solute)
Organic liquids with weak intermolecular forces are said to be….
Non-polar
Organic liquids that have very strong intermolecular forces are said to be…
Highly polar
Non-polar solvents are best for dissolving…
Non-polar compounds
Polar solvents are best for…
Polar compounds
T/F Organic compounds only have one type of intermolecular force each
False; may have multiple types of intermolecular forces arising from having multiple functional groups
Ionic compounds like organic _______ will usually dissolve in highly _____________ solvents.
Salts; polar
Why do Ionic compounds dissolve well with water being the solvent?
Because the attractive interaction between the non-bonded pairs and the polarized hydrogens of water
Define Dielectric Constant
A physical measurement of how a substance interacts with an electric field
What can Dielectric Constant be used for?
Used to compare the polarity of different solvents
The better a molecule insulates the ___________ the dielectric constant.
Higher
Think of Dielectric constant as the measurement of a solvents…
Ability to balance part of the solute’s charge
Define Hydrogen Bond Donor
A hydrogen attaches to an electronegative atom
It’s reason for these trends in the dipole moments and Dielectric constants is due to the…
Electronegativity differences of individual atoms within each molecule
Ex. C and H have relative similar electronegativity values so the C-H bond is essentially…
Non-polar
Non-polar molecules share their electrons ____________.
Evenly
An O-H bond is polarized since…
The O is more electronegative than H
In an O-H bond, since O is more electronegative, the electrons are polarized towards the ____ and becomes partially _____________.
O; negative
An _________ is a good way of showing the polarity of a bond in illustrations.
Arrow
____________ is the most electronegative atom on the periodic table.
Fluorine
Is a bond has a Fluorine it will _______ electrons ________ from the carbon and the arrow points towards the ____.
Pull; away; F
Is arrow points towards F and away from C, F is ______________ and ________________.
Electronegative; electropositive
Define Dipole Moment Arrow
Arrow that is drawn on an entire molecule
__________ and ______________ derivative molecules are also good ways to illustrate molecule polarity.
Allene; Benzene
The Para substitution pattern is overall ______ polar than the Ortho substitution pattern.
Less
The Meta substitution pattern is ______________ in polarity.
In between
In the Para di-substitution molecule, the dipoles cancel each other out so the overall polarity is _________.
Small
In the Ortho isomer substitution molecule. The partial charges add so….
The overall polarity is higher
Ortho and Meta substitution patterns are __________ at room temperature.
Liquid
Para isomer is __________ at room temperature.
Would
Define Chemical Informatics
Knowing what a molecules density is, what its boiling point is and what kinds of other molecules it will dissolve
If a substance is more dense, it will _______. If a substance is less dense it will _______.
Sink; float
When it comes to enhancing water solubility are HBA’s important, are HBD’s important, both or neither?
HBA’s are not as important as HBDs
To find the number of HBDs you must…
Count the Hs on Os (alcohols/acids) or Ns (amines/amides)
To find the number of HBAs you must…
Count the number of non-bonded pairs on the Ns and Os
