Ex. HCL: Hydrochloric acid
What is the molar mass of C8H18?
8(12.01g/mol) + 18(1.01 g/mol)= 114.22 g/mol
Glucose formula: C6 H12 O6
Therefore 1 mole of Glucose…
Is 6 mole of C
Is 12 mol of H
Is 6 mol of O
Empirical and Molecular formula
Empirical formula: the simplest ratio present
Molecular formula: n (empirical formula)
Ex: C6H12O6 = 6 (CH2O) Don't forget about the age old question of What are the police misconducts identified by ellwyn stoddard?
Molar mass: n (empirical mass)
Ex: (6 x 12.01 g/mol) + (12 x 1.01 g/mol) + (6 x 16.000 g/mol) = 180.16 g/mol (MOLAR MASS)
We also discuss several other topics like How are the structures of the bones characterized?
Ex. (1 x 12.01 g/mol) + (2 x 1.01 g/mol) + (1 x 16.000 g/mol)= 30.03 g/mol (EMPIRICAL MASS)
Examples: What’s the empirical and molecular formula of the following compound? 26.7% P, 12.2% N, 61.2% Cl Molar Mass: 580 g/mol
Strategy: Assume 100 g of compound
P: 26.7 g; N: 12.2 g; Cl: 61.2 g
P: 26.7 x 1mol/30.97 g =0.862 mol P
N: 12.2 x 1mol/14.01 g =0.864 mol N
Cl: 61.2 x 1mol/35.45 g =1.73 mol Cl
Divide by smallest number: 0.862
P: 0.862/0.862 N: 0.864/0.862 Cl: 1.73/0.862=
P1 N1 C2 ---->> EMPIRICAL FORMULADon't forget about the age old question of How the allocation of resources affects economic well being?
Molar mass= n ( empirical mass)
580 g/mol= n (30.97g/mol + 14.01 g/mol + 2(35.45g/mol)) If you want to learn more check out What is ecological hierarchy?
580 g/mol= n (115 g/mol)
n= 5.04--------> 5
Limiting reactant: reactant that is entirely used up and makes less product Theoretical yield: maximum amount you can make Don't forget about the age old question of Where is the temperate broadleaf forest?
Percent reactant: actual yield/ theoretical yield x 100%
Excess reactant: reactant that has left overs
How to balance equations: ____Fe (s) +___ O2 (g) ------>>> ___ Fe2O3 (s) 1. Start with 1.00 mol O2, How many moles Fe needed?
1.00 mol O2 x 4 mol Fe/ 3 mol O2 = 1.33 moles of iron
2. Start with 100 g O2, How many grams Fe needed?
100.0 g O2 x 1 mol O2/ 32.00 g x 4 mol Fe/ 3 mol O2 x 55.85 g Fe/ 1 mol Fe= 232.7 grams Fe Don't forget about the age old question of Why are the offspring of sexual reproduction not perfect copies of their parents?
3. Start with 32.7 grams O2 with 54.1 grams Fe, How much Fe2O3 possible?
(54.1x 1 mol)/
0.295x 32.00 g/ 1 mol
0.484 x 159.70g/1 mol
__4__Fe (s) +_3__ O2 (g) ------>>> _2__ Fe2O3 (s)
Chapter 5: Solutions
Solution: homogeneous mixture of solvent and solute
Solvent: large amount of what is dissolving solute (Ex. water)
Solute: smaller quantity
Molarity (M): moles of solute/ L of solution
Ex. 0.500 M NaCl, whats the molarity of Na+ and Cl-?
0.500 M for each
DISSOLVE VS DISSOCIATE
Dissolve: solid and solvent form homogeneous mixture
Dissociate: ionic compound falls apart into ions as it is dissolved in solution
Electrolytes- solution that contains ions
Strong electrolytes: “fully dissociate”
= solution that conducts electricity
Weak electrolytes: “partially dissociates”
Non- electro. : does not dissociate (Ex. sugar, gasoline, oil) ;won’t conduct electricity
NaCl ( table salt ) in H20 will dissociate because it is ionic ( NaCl------>> Na+ + Cl-) C12H24O12 (sugar/sucrose) won't dissociate but will dissolve
1.anything (anion) with group 1 cation( Li+, Na+, K+) and ammonium 2. anything (cation) with nitrate or acetate
3.Group 17 anion
Exception:Ag+, Hg2^2+, Pb^2+
*Strong acid: HCl, HI, HNO3, H2SO4, HClO4 (MEMORIZE)
Weak acid: everything else
Strong base: NaOH, LiOH, KOH, Ca(OH)2
Weak base: NH3
acid+ base-----> H2O +SOH
Strong acid + Strong Base
Ex. HCL + NaOH---> H20 +NaCl
H + Cl + Na+ OH -----> H2O + Na +Cl
CROSS OUT REPEATS!
H+ OH----> H2O
Oxidation state= Oxidation number : ELECTRONS!!
Oxidation number= charge on ion!!! (sign first)
1.Neutral elements have oxidation of 0
Ex. H2, He, Fe
a.Ex. H+, Na+, K+, Li+---≥ lose one electron so oxidation is +1
b.F-, Cl-, Br-, I- ----> gain electron so oxidation is -1
3. H in molecule is +1
4.O in molecule is -2
6.Group 1: +1
7.Group 2: +2
Pressure(atm) x volume( L)= mols of gas(mols) x gas constant (0.08206) x temperature (K) 1 atm= 760mmHg
Ex. If you fill a balloon with 5.00 grams of He gas at 298 K and 1.00 atm pressure, what's the V of the balloon?
P= 1.00 atm
n= 5.00 g x 1mol/4.00 g= 1.25 mols
T= 298 K
V= 30.6 L
Collecting gas over water
Ptotal = Pgas( from reaction) + PH2O( evaporate)
Theory of Gas:
1. The size of a gas atom/ molecule is really tiny compared to the volume of gas 2. The average kinetic energy of atom/molecule depends on temp of gas 3. (KE=.5mv^2)(higher temp means higher velocity and higher KE)
4. Same temperature, different gas
a. KEgas1= KEgas2….
5. Same gas, different temperature