MCAT Study Guide Chemistry Ch. 3 – Basics 2017-08-15T06:45:06+00:00

I.          3.1  METRIC UNITS

 

II.          3.2 DENSITY

 

III.          3.3 EMPIRICAL FORMULAS

A.     Empirical formula – the lowest ratio of atoms in a molecule

 

IV.          3.4:  FORMULA AND MOLECULAR WEIGHT

A.     Formula weight – sum of the atomic weights of all the atoms in the molcule

B.     Atomic mass unit – 1 amu = 1/12 the mass of a carbon-12 atom

 

V.          3.5: THE MOLE

A.     Avogadro’s number = 6.02 * 1023 entities

 

VI.          3.6:  PERCENTAGE COMPOSITION BY MASS

 

VII.          3.7:  CONCENTRATION

A.     Molarity = moles/(volume
[L] solution)

B.     Molality = moles/(weight [kg] of solvent)

C.    Mole fraction – way to express a concentration when more than one solute is present

 

VIII.          3.8:  CHEMICAL EQUATIONS AND STOICHIOMETRIC COEFFICIENTS

 

IX.          3.9:  STOICHIOMETRIC RELATIONSHIPS IN BALANCED REACTIONS

 

X.          3.10:  THE LIMITING REAGENT

 

XI.          3.11:  SOME NOTATION USED IN CHEMICAL EQUATIONS

 

XII.          3.12:  OXIDATION STATES

A.     Meant to indicate how the atom’s “ownership” of its valence electrons changes when it forms a compound

B.     Rules:

1.     The oxidation state of any element in its standard state is 0

2.     The sum of the oxidation states of the atoms in a neutral molecule must be 0, and the sum of the oxidation states of the atoms in an ion must always equal the ion’s charge

3.     Group 1 metals have a +1 oxidation state

4.     Group 2 metals have a +2 oxidation state

5.     Hydrogen has a +1 oxidation state when bonded to something more electronegative than C

6.     Hydrogen has a -1 oxidation state when bonded to something less electronegative than C

7.     Hydrogen has 0 oxidation state when bonded to C

8.     Oxygen has -2 oxidation state

9.     The rest of the halogens have a -1 oxidation state and atoms of the O family have a -2 oxidation state

(a)   **In peroxides, O has -1 oxidation state

MCAT Study Guide Chemistry - Kim Matsumoto


More MCAT Study Guide Chemistry

1.

Ch. 3 Chemistry Basics

2.

Ch. 4 Atomic Structure

3.

Ch. 5 Chemical Bonds

4.

Ch. 6 Enthalpy + Entropy

5.

Ch. 7 Calorimetry + Phase Diagrams

6.

Ch. 8 Ideal Gas Law

7.

Ch. 9 Rate Laws

8.

Ch. 10 Equilibrium

9.

Ch. 11 Acids and Bases

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