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)
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)
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 FORMULA
Molar mass= n ( empirical mass)
580 g/mol= n (30.97g/mol + 14.01 g/mol + 2(35.45g/mol)) Don't forget about the age old question of What are the police misconducts identified by ellwyn stoddard?
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
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 Don't forget about the age old question of How is eversion performed?
2. Start with 100 g O2, How many grams Fe needed? If you want to learn more check out How the allocation of resources affects economic well being?
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
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
If you want to learn more check out What are types of species distribution patterns?
__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 Don't forget about the age old question of Where is the temperate broadleaf forest?
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+
1.OH-, S2- We also discuss several other topics like Why are the offspring of sexual reproduction not perfect copies of their parents?
*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