Things you need to review Before IB Chem -11 Concepts and notes are in bold. Problems you should try and solve are in normal font. Special directions are in italics. If there are significant issues, please e-mail me: [email protected] Have a good summer, Mr. Capello

I. Prefixes Prefixes a) b) c) d) e) f) g) h)

Mega, 106, M Kilo, 103, k Deci, 10-1, d Centi, 10-2, c Milli, 10-3, m Micro, 10-6, μ (mew) Nano, 10-9, n Pico, 10-12, p

1 mL = 1cc = 1 cm3

Convert the following: 6.7 cm → dm

0.54 kg → g

5.95*108 µL → kL

1.323 Mg/L → mg/cm3

1.79*1032 pm/ns → km/h

II. Scientific Precision A. Accuracy – refers to the closeness of a measurement to the true or accepted value of the quantity measured (how close to right) B. Precision – refers to the agreement among the numerical values of a set of measurements of the same quantity made in the same way (how close to others). C. Significant Figures 1. Rules a. If the number is less than one, the first nonzero number to the right of the decimal is significant and all numbers following are significant. b. If the number is greater than one, every number is significant 2. Calculations a. Addition and subtraction – give as many sig figs in the answer as there are in the measurement with the least number of decimal places. b. Multiplication and division – give as many sig figs in the answer as there are in a measurement with the least # of sig figs. 3. Exact Numbers a. A number that arises from counting or conversion factor ex// how many students in the classroom

b. Ignore exact numbers when doing sig fig calculations D. Percent Error 1. a judgment of accuracy based on a comparison with the accepted value 2. %Error = | Accepted – Experimental | /Accepted * 100

How many sig figs?

Calculate with the correct sig figs?

0.005 = 0.0050 = 123. = 10. =

5.00 cm + 7.113 cm = 27.8252 L - 5.1 L = 3.975 kg * 2.2 kg= 315.29754 m /5.746 m =

The melting point of a chemical is 53.0°C. Two students try to determine this value experimentally doing 5 trials. Student A gets 54.9°C, 54.7°C, 55.0°C, 54.8°C, and 55.1°C. Student B finds 52.3°C, 53.2°C, 54.0°C, 52.5°C, and 53.5°C. Calculate the average value for each student. Using the average value, determine each student’s percent error. Which student is more precise, which is more accurate?

Memorize:

III. Polyatomic Ions

Ammonium – NH4+ Hydroxide – OHPermanganate – MnO4Nitrite – NO2-

Nitrate – NO3-

Sulfite – SO32-

Sulfate – SO42-

Carbonate – CO32Bicarbonate or hydrogen carbonate HCO3Phosphate – PO43Hypochlorite – ClO-

Chlorite – ClO2-

Chlorate – ClO3-

Perchlorate – ClO4-

Cyanide – CNChromate – CrO42Thiosulfate – S2O32-

IV. Nomenclature A. Monatomic ion 1. Review charges on periodic table 2. If cation, name stays the same 3. If anion, name adds -ide to end B. Binary ionic compounds 1. Write down charges 2. Find LCD 3. Use factor as subscript 4. Take name of cation and name of anion 5. Examples: LiF; BaO; Al2O3; Na2O; AlI3; MgCl2; K3N C. Multivalent compounds 1. Look at charge of anion 2. Discover charge of transition metal 3. Find LCD 4. Use factor as subscript 5. Take name of metal (Roman numeral) anion name 6. Examples: CuCl; CuCl2; FeO; Fe2O3; ZnS; Zn2S D. Polyatomic Ion Compounds 1. Write down charges 2. Find LCD 3. Use factor as subscript with polyatomics in () if subscript is other than one 4. Take name of cation and name of anion 5. Ex: NaNO3; MgCO3; Ca(BrO3)2; K2SO4; (NH4)3PO4 E. Covalent Compounds 1. Prefixes a. 1 = mono f. 6 = hexa b. 2 = di g. 7 = hepta c. 3 = tri h. 8 = octa d. 4 = tetra i. 9 = nona e. 5 = penta j. 10 - deca 2. Provide less electron negative element first 3. Add a prefix to that element if the subscript is other than 1 4. Give more e-negative element with prefix, name, & ide 5. Ex: NO, N2O; NO2; N2O3, N2O4; N2O5; P4O10; OF2; SO3 F. Acids 1. Binary acid – H plus some single element a. Add the prefix hydro and change the anion to –ic b. HF, HCl, HBr 2. Oxyacids – H plus a polyatomic ion a. If the polyatomic ends in -ite change to –ous b. If the polyatomic ends in –ate change to -ic

Name these examples B. Binary ionic compounds LiF

AlI3

BaO

MgCl2

Al2O3

K3N

Na2O C. Multivalent compounds CuCl

Fe2O3

CuCl2

FeO

D. Polyatomic Ion Compounds NaNO3

K2SO4

MgCO3;

(NH4)3PO4

Ca(BrO3)2 E. Covalent Compounds NO

N2O5

N2O

P4O10

NO2

OF2

N2O3

SO3

N2O4 F. Acids 1. Binary acid HF

HCl

HBr 2. Oxyacids H2SO3

H2CO3

H2SO4

HClO

H3PO4

HClO2

HNO2

HClO3

HNO3

HClO4

NO – name cation first

Add –ide to anion

YES – use Roman Numerals to explain charge

Add –ide to anion

If ionic, is it a transitional metal? Then, name more electroneg. element

ALWAYS use prefix and add -ide

First, name less electroneg. element

Add prefix if subscript is other than one

Covalent

Is it an ionic bond, covalent bond, or acid?

Nomenclature

Add hydro + halogen +ic +acid

Is it binary, H+ halogen

Balance charge of polyatomic with H’s

Is it oxy, H+ polyatomic

ite = ous+acid ate = ic+acid

Acid

V. Measurement and Units

A. Base Units 1. Groups a) Length – meter, m b) Mass - kilogram, kg c) Time – second, s d) Temperature - kelvin, K i. K = ˚C + 273 ii. ˚F = (1.8 * ˚C) + 32 iii. ˚C = (˚F – 32) / 1.8 (e) Amount of substance - mole, mol (f) Electric current – ampere, A (g) Luminous intensity – candela, cd

B. Derived Units – combinations of SI base units 1. Volume, cubic meter, m3, l*w*h a) 1 mL = 1 cc = 1 cm3 b) 1 dm3 = 1 L = 1000 mL = 1000 cm3 2. Density, mass per unit volume, kg/m3, g/cm3 a) d = m/v 3. Velocity, distance traveled per unit time, m/s 4. Acceleration, velocity changed per unit time, m/s2 5. Pressure, force per unit area, pascal, Pa = kg/(m*s2) 6. Energy, force times length = joule, J = kg*m2/s2 a) 1 calorie (cal) = 4.184 J b) 1 Calorie = 1 kcal = 1000 cal = 4184 J 8. Concentration, amount per volume, mol/dm3 or moldm-3

VI. Ionic Bonding A. Definition – bonding that results from electrical attraction between (+) ions (cations) and (-) ions (anions) 1. Cations – 1+, 2+, 3+ - P.T. Trends – show valence e- and dots 2. Anions – 3-, 2-, 1- - Same as above B. Difference in e-neg >1.7 ex:// Na=.9 and Cl=3.0 C. Typically the joining of a metal (left of staircase) and a nonmetal (right of staircase) D. Ionic Compound – a substance where the total combination of cations and anions equal to zero E. The How-To of Ionic Formation 1. Draw dot diagram of each atom participating in bond (Reactants) 2. Determine if it is easier to go to zero or eight and how best to get there 3. Set up reactants with dots 4. Set up products with dots and charges as necessary. 5. Do the charges add up to zero? F. Crystal Lattice 1. A 3-D arrangement so that each (+) charged ion is surrounded by (-) ion and vice versa 2. Lattice energy – the energy required to separate 1 mol of ions from an ionic compound – the greater the E, the greater the force of attraction, the hard to break 3. Lattice energy is based on ion size and charge a. Smaller ions – greater E – KF vs RbF b. Greater charge – greater E – NaI vs MgO G.

Polyatomic ions – a group of atoms with a charge

H.

Transitional Metals – multivalent charges

VII. Metallic bonding A. B.

Metals form lattice structures and are based on electrical attraction Electron sea model 1. Valence e- are not attached to specific metal cations instead e- can move freely about – as if the cations were like buoys surrounded by a sea of electrons 2. Because the electrons do not have a specific cation they are attached to, they are called delocalized electrons C. Metallic bond – attraction of a metallic cation to delocalized e- which helps explain most of the properties of metals D. Alloys 1. A mixture of elements that have metallic properties 2. Substitutional alloy – different metal cations of similar size are combined 3. Interstitial alloy – smaller atoms fill the holes in the metal lattice 4. Examples a. Brass – Cu and Zn b. Bronze – Cu, Zn, and Sn c. Gold – only 24 carat is pure d. Pewter – Sn, Sb, and Pb e. Stainless Steel – Fe, Cr, and Ni

VIII. Covalent Bonding A. Bonding that results from the sharing of e- between atoms usu. between two nonmetals B. Types 1. Polar a. e- are unevenly shared resulting in a slight charge b. 0.3 < Difference < 1.7 c. H = 2.1 and Cl = 3.0 2. Nonpolar a. e- equally shared resulting in a balanced distribution of charge b. e-neg < 0.3 c. H2 C. Basic Definitions 1. Molecule – a neutral group of atoms held together by covalent bonds 2. Chemical Formula – indicates the relative numbers of each kind of atom in a chemical compound by using atomic symbols and numerical subscripts 3. Diatomic Molecule – a molecule containing only two atoms 4. Bond Length a. the average distance between two bonded atoms at their minimum potential energy b. Single bonds are longer; triple bonds are shorter

5. Bond Energy a. The energy required to break a bond and form neutral isolated atoms. b. Single bonds have the least E; triple the most D. Dot Diagrams 1. Lewis Definitions a. Lewis dot diagram – a positioning of atomic symbols using e-pairs or dashes to represent bonds between atoms and adjacent pairs to represent nonbonding eb. Shared pair or bonding e- - pairs of e- that act as a bond between atoms c. Unshared, lone, or nonbonding e- pair – e- necessary to fill octets but not used in the bonding of atoms 2. Octet Rule a. Chemical compounds tend to form so that each atom has 8 e- in its valence shell b. Exceptions: H, Ne, B, among others 3. Steps a. Add up all of the valence eb. Choose central atom c. Position other atoms around central d. Bind each atom singly to central and subtract e. Fill octet of surrounding atoms and subtract f. Attempt to fill octet of central atom g. Check for multiple bonds or ion formation h. Recount to 8 4. Single Bonds – a covalent bond produced by the sharing of one pair of e- between two atoms: F2; HF; H2O; NH3; CF4 5. Multiple Bonds a. A covalent bond produced by the sharing of two (double) or three (triple) pairs of e- between atoms that usually only occurs with C, N, S and O b. e- count used up but an atom still has an unfilled octet and the combination is not recognized as a polyatomic ion c. Examples: CO2 O2 N2

IX. Reactions Types A. Synthesis 1. Definition – two or more substances that combine to form a new compound 2. Generic formula – A + X -> AX B. Decomposition 1. Definition – a single compound undergoes a rxn to produce two or more simpler substances 2. Generic – AX -> A + X C. Single-Replacement 1. Definition – when one element takes the place of a similar element in a compound 2. Generic Formula – A + BX  AX + B D. Double-Replacement 1. Definition – the ions of two compounds exchange places to form two new compounds 2. Generic Formula – AX + BY  AY + BX E. Combustion 1. Hydrocarbons – a compound that has only C’s and H’s in it 2. General formula – Hydrocarbon + Oxygen  Carbon dioxide + Water F. Neutralization - An acid and base combine to form salt and water

X. Activity Series A. List of elements organized according to the ease in which they react B. Helps determine whether a reaction will work or not

Images taken from Advanced Chemistry Clugston and Flemming (226)

Will these reactions occur or not? If so, predict the products and balance. K + BaO  Na + CaO  F2 + 2NaCl  Br2 + KCl 

XI.VSEPR A. Valence shell electron pair repulsion (VSEPR) explains the shapes of molecules B. The shape will help indicate the properties of molecules C. Based on the idea that bonding pairs take up less space than lone pairs and the negative charges spread out in space as much as possible D. To predict shape 1. Draw covalent structure 2. Count shared vs. unshared pairs on the CENTRAL ATOM 3. Double and triple bonds count as one shared pair 4. Consult table

Solve these probems: Density What is the density of sunflower oil if it has a mass of 116.0 g and a volume of 125.0 mL? If the known density of sunflower oil is 0.919 g/mL, what is the percent error of this experiment?

What is the volume of a sample that has a mass of 20.0 g and a density of 4.0 g/mL?

A piece of aluminum is placed in a graduated cylinder that contains 10.5 mL of water. After placing the aluminum in the cylinder the new measurement of the water in the cylinder is 13.5 mL. The density of aluminum was looked up and found to be 2.7 g/mL. What was the mass of the aluminum placed in the cylinder?

Draw and name the following. Also determine the electron domain and molecular geometries: F2

NH3

CF4

CO2

N2

NH4+

PO43-

Balance and understand the following reaction types: Synthesis Subtypes a. Metal i. ii. iii.

+ Oxygen Mg + Fe + Fe +

yields a metal oxide O2  O2  O2 

b. Metal + Sulfur yields a metal sulfide i. Rb + S8  ii. Ba + S8  c. Metals + halogens yields a salt i. Na + Cl2  ii. Mg + F2  d. Metal Oxides + water yields a metal hydroxide i. Na2O + H2O  ii. CaO + H2O  e. Nonmetal Oxides + water yields oxyacids i. SO2 + H2O  ii. P4O10 + H2O  Decomposition Subtypes a. Binary Compounds to individual elements i. H2O  ii. HgO  b. Metal Carbonates yield metal oxide and carbon dioxide i. CaCO3  ii. Na2CO3  c. Metal Hydroxides yield metal oxide and water i. Ca(OH)2  ii. NaOH  d. Metal Chlorates yield metal chloride and oxygen i. KClO3  ii. Mg(ClO3)2  e. Oxyacids yield nonmetal oxides and water i. H2CO3  ii. H2SO4 

Single Replacement Subtypes a. A metal replaces a metal i. Al + Pb(NO3)2  b. A metal replaces aqueous H to form a metal hydroxide and hydrogen gas i. Na + H2O  c. A metal replaces acidic H to form a salt and hydrogen gas i. Mg + HCl  d. Halogen replacement i. Cl2 + KBr  Double Replacement Subtypes a. Formation of a precipitate i. KI + Pb(NO3)2  b. Formation of a gas i. FeS + HCl  c. Formation of water i. HCl + NaOH  Combustion Examples a. CH4 + b. C3H8 + c. C8H18 +

O2  O2  O2 

Neutralization Examples a. HCl + NaOH  b. Mg(OH)2 + HNO3  These are the very basic of concepts you should understand. Other topics we will be covering in the first month which should be somewhat familiar to you are stoichiometry and limiting reactant problems. Here are some websites to look over if those concepts are foreign to you: http://www4.ncsu.edu/~franzen/public_html/CH201/prac/Limiting_Reagent_Worksheet.pdf https://www.everettcc.edu/files/students/rainier-learning-center/tutoringcenter/chemistry/w324-limiting-reagent-worksheet.pdf https://smccd.mrooms.net/pluginfile.php/584957/mod_resource/content/1/StoichiometryWo rksheet1.pdf