Practice Test Review (Chemical and Physical) Flashcards
How do you find molarity?
Find the total mass of the compound and divide by that compounds molar mass (g/mol), which is calculated via the periodic table
What does absorption of salt in the blood cause?
The blood to become hypertonic, causing osmosis of water out of the cells
What is alpha decay?
An alpha particle (two protons, two neutrons, 2+ charge) is emitted
What is beta-minus decay?
What is beta-plus decay?
Beta-plus: Proton is converted to a neutron, a beta+ particle (positron) is emitted.
Beta-minus: Neutron is converted into a proton, a beta- particle (electron) is emitted.
What is gamma decay?
A gamma ray (high energy photon) is emitted from an excited nucleus.
What is electron capture decay?
A nucleus “grab” an electron, which changes a proton into a neutron.
What is a half-life?
Time required for one-half of the parent isotopes in a sample to decay into daughter isotopes
General MCAT Tip:
When asked a specific question about research design or execution (not testing over knowledge), choose an answer that can be inferred from the text, rather than an obscure guess that makes sense
What is chiral?
A carbon attached to four different groups.
How do you find the amount of stereoisomers for a molecule?
2^n the amount of chiral centers
What do l and d mean in terms of chirality?
Compounds that produce clockwise (+) rotation of light are dextrorotatory, compounds that produce counterclockwise (-) rotation of light are levorotatory
What are boiling chips used for in distillations?
Provide nucleation sites that give the liquid a place to start forming bubbles to prevent superheating
What is vacuum distillation used for in distillations?
Lower the boiling points of the substances to be distilled. (Reduces the atmospheric pressure)
When does boiling occur?
What the vapor pressure of the substance equals the atmospheric pressure.
In distillation procedures, which compound boils off first?
The one with the lower boiling point.
How do you compare the boiling/melting point between two compounds?
Functional groups with hydrogen bonding have higher boiling/melting points. Nitrogen containing compounds have medium melting/boiling points.
How do you determine formal charge?
valence electrons - sticks - dots.
How do you determine the amount of valence electrons?
The main group number (Main groups are numbered 1 - 8, skipping over the transition metals)
How do you calculate gravitational potential energy of a mass?
Mass * g * height
How do you calculate kinetic energy of a mass?
1/2 Mass * velocity^2