gen chem chapter 4 mcat

compounds

substances composed of two or more elements in a fixed proportion

molecular weight

the mass (in AMU) of the constituent atoms in a compound as indicated by their molecular formula

molar mass

the mas of one mole (avagadros number) of a compound

6.022 × 10²³

avagadro’s number

gram equivalent weight

is a measure of the mass of a substance that can donate one equivalent of the species of interest

normality

the ratio of equivalents per liter; it is related to morality by multiplying the morality by the number f equivalents present per mole of compound

equivalents

moles of the species of interest; most often seen in acid-base chemistry and oxidation reduction reactions

law of constant composition

states that any pure sample of a compound will contain the same elements in the same mass ratio

empirical formula

the smallest whole number ratio of the elements in a compound

molecular formula

either the same as or a multiple of the empirical formula; it gives the exact number of atoms of each element in a compound

combination reactions

occur when two or more reactants combine to form one product

decomposition reactions

occur when one reactant is chemically broken down into two or more products

combustion reactions

occur when a fuel and an oxidant (typically oxygen) react forming the products water and carbon dioxide (if the fuel is a hydrocarbon)

displacement reactions

occur when one or more atoms or ions of one compound are replaced with one or more atoms or ions of another compound

single displacement reactions

occur when an ion of one compound is replaced with another element

double displacement reactions

occur when elements from two different compounds trade places with each other to from two new compounds

neutralization reactions

an acid reacts with a base to from a salt (usually water)

limiting reagent

the reactant that will be consumed first in a chemical reaction

theoretical yield

= Moles of Product x Molar Mass of Product. This equation calculates the maximum amount of product that can be produced from a given amount of reactants, assuming perfect reaction conditions and no losses during the reaction or isolation of the product

actual yield

(Percent Yield / 100) * Theoretical Yield

percent yield

(Actual Yield / Theoretical Yield) * 100. This equation helps determine the efficiency of a chemical reaction by comparing the amount of product actually produced (actual yield) to the maximum amount theoretically possible (theoretical yield). 

metals

form positively charges cations based on group number

nonmetals

form negatively charged anions based on the number of electrons needed to achieve an octet

electrolytes

contain equivalents of ions from molecules that dissociate in solution. The strength depends on the degree of dissociation or solvation