CHAPTER 4

oxidation. reduction. redox reactions

are defined as homogeneous mixtures of two or more pure substances.

barium hydroxide solution liquid aluminum chloride liquid sodium oxide magnesium chloride solution sulfuric acid

ammonia solution vinegar

argon gas glucose solution water ethanol

Molecular compounds which are weak acids or weak bases. Or Molecular compounds exclude strong electrolytes and nonelectrolytes. Common weak acids: H2CO3, HNO2, H2S, CH3COOH, HF, H3PO4, etc. Common weak base: NH3 (some people write it as NH4OH.

sugar ( -ose), acetone ( -one), alcohol ( -ol), ether ( -O- ) etc.

(1) All ionic compound and (2) Molecular compounds which are strong acids: HNO3 H2SO4, HCl, HBr, HI, HClO3, HBrO3, HlO3, HClO4, HBrO4, HlO4. Note: Strong bases (IA & IIA metal oxides and metal hydroxides) are ionic compounds: For examples: NaOH, KOH, Ca(OH)2, Sr(OH)2, Ba(OH)2 etc.

is a substance that dissociates into ions when dissolved in water.

compounds exchange, or transpose, ions, as seen in the equation below. AgNO3(aq) + KCl(aq) --> AgCl(s) + KNO3(aq

AgNO3(aq) + KCl(aq) AgCl(s) + KNO3(aq)

all strong electrolytes (strong acids, strong bases, and soluble ionic salts) are dissociated into their ions. This more accurately reflects the species that are found in the reaction mixture. Ag+(aq) + NO3?(aq) + K+(aq) + Cl?(aq) --> AgCl(s) + K+(aq) + NO3?(aq)

cross out anything that does not change from the left side of the equation to the right. called spectator ions, K+ and NO3?, in this example. Ag+(aq) + NO3?(aq) + K+(aq) + Cl?(aq) --> AgCl(s) + K+(aq) + NO3?(aq)

Hydrochloric Acid, HCl Hydrobromic Acid, HBr Hydroiodic Acid HI Chloric Acid, HClO3 Perchloric Acid, HClO4 Nitric Acid, HNO3 Sulfuric Acid H2SO4

a> cation = Ni^2+, anion = SO4^2- so 6x2+ requires 12/2 = 6 anions. (also the formula indicates a 1:1 ratio) b> cation = Ca^2+, anion = NO3^1- so 6x2+ requires 12/1 = 12 anions. c> cation = Na^1+, anion = PO4^3- so 6x1+ requires 6/3 = 2 anions. d> cation = Al^3+, anion = SO4^2- so 6x3+ requires 18/2 = 9 anions

neutralization reactions.

When a strong acid (like HCl) reacts with a strong base (like NaOH), the net ionic equation is circled below: HCl(aq) + NaOH(aq) NaCl(aq) + H2O(l) H+(aq) + Cl?(aq) + Na+(aq) + OH?(aq) Na+(aq) + Cl?(aq) + H2O(l) H+(aq) + OH?(aq) H2O(l)

A)H2 Molecular compounds exclude strong and weak electrolytes; noble gases, H2, O2, N2, etc.

NaOH (sodium hydroxide) KOH (potassium hydroxide) LiOH Ba(OH)2 Ca(OH)2

HF (hydrofluoric acid) HC2H3O2 (acetic acid) H2CO3 (carbonic acid) H3PO4 (phosphoric acid) weak bases NH3 (ammonia) ("N" compounds) C5H5N (pyridine)

sugars and carbohydrate C6H12O6 (glucose) fats and lipids cholesterol alcohols C2H5OH (ethyl alcohol) other carbon compounds C5H12 (pentane)

salts NaCl KBr MgCl2

Na2CO3 is soluble in water. PbSO4 is insoluble in water.

_(a) insoluble, (b) soluble, (c) soluble

B

Cu(s) + 2 Ag+(aq) Cu2+(aq) + 2 Ag(s) Displacement Reactions The reverse reaction does NOT occur

oxidation: loss of electrons,reduction: gain of electrons

The quantity of solute in a solution can matter to a chemist. We call the amount dissolved its concentration. Molarity is one way to measure the concentration of a solution: M= moles of solute/volume of solution in liters

One can also dilute a more concentrated solution by using a pipet to deliver a volume of the solution to a new volumetric flask, and adding solvent to the line on the neck of the new flask

The molarity of the new solution can be determined from the equation Mc Vc = Md Vd, where Mc and Md are the molarity of the concentrated and dilute solutions, respectively, and Vc and Vd are the volumes of the two solutions.

is an analytical technique in which one can calculate the concentration of a solute in a solution. solution of known concentration, called a standard solution, is used to determine the unknown concentration of another solution. The reaction is complete at the equivalence point.

Mn(OH)2

MgSO4(aq) and Pb(NO3)2(aq) NaCl(aq) and AgNO3(aq) Ca(OH)2(aq) and K2CO3(aq)

Na2S (aq) and HCl (aq) Na2CO3 (aq) and HCl (aq) NH4Cl (aq) and NaOH (aq)

1.50/1000=*500*3