DOC PREVIEW
UB CHE 101 - Exam 1 Study Guide

This preview shows page 1-2 out of 5 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 5 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 5 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 5 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

CHE 101Exam # 1 Study Guide Chapters: 1-5Chapter 1 Matter & Elements- Diatomic molecules are gases in natural state (H2, N2, O2, F2, Cl2, Br2, I2)- Significant Figures: (sig figs) create a more precise measuremento Can use scientific notation to clarify (ex: 0.0930 has 3 sig figs = 9.30*10-2)Chapter 2 Atoms, Molecules and Ions- Mass number: sum of protons and neutrons for specific atom- Atomic number: protons in nucleus- To name a specific atom: element name-mass # (ex: magnesium-24)-Isotopes: same number of protons but different number of neutrons- Atomic mass accounts for all isotope in elementoAW =∑isotopemass∗isotopeFA- Molecular formula: actual number of atoms inmolecule- Empirical formula: lowest ratio of atoms in moleculeNaming- General naming rule: 1st element name unchanged and 2nd ends in –ide, -ate or –ite- Compounds: 7 diatomic gases, molecular (nonmetal), ionic (nonmetal + metal), acid- Molecular: generally end in –ide and use prefixes# 1 2 3 4 5 6 7 8 9 10Prefix Mono D Tri Tetra Penta Hexa Hepta Octa Nano DecaAtomic #SymbolMass #1H1.008massatomic¿¿¿¿ symbol2412MFA=fractional abundancei- Ionic:o Cations (metals) lose electrons = positive ion Monoatomic ions naming: unchanged element name + ion Use roman numerals for multiple charges (ex: cobalt (III) ion)o Anions (nonmetals) gain electrons = negative anion Monatomic ions naming: element-ide + ion(ex: chloride ion)o Polyatomic naming: cation anion Cation: unchanged + roman numeral Anion: monoatomic= -ide & polyatomic= -ateor –ite If the polyatomic ion name ends in “o” compound ends in –ate Positive ion = -ium ending Non-oxygen, negative ion = -ide ending Lose 1 O = -ite (BrO2-, bromite) Lose 2 O = hypo-, -ite (BrO-, hypobromite) Gain 1 O = per- (BrO4-, perbromate) Gain H = hydrogen- (HBrO3-, hydrogen bromate)- Add 1+ for each H to total charge- Acids: o Binary acids have hydro- & -ic acid (HCl, hydrochloricacid)o Polyatomic acids have no extra prefixes, keep existing -ate  -ic acid -ite  -ous acid HClO3, chloric acid HClO, hypochlorous acidChapter 3Stoichiometry: Conversions with Chemical Formulas and Equations- Formula/ Molecular weight= ∑(¿ of atoms)( AW ) same as molar mass (g/mol)- Percent composition = (¿ of atoms)( AW )FW∗100- Avogadro’s number = 6.022*1023 = 1 mol- Element= atom & compound = molecule- MF = EFx (molecular formula = empirical formula * constant)o Find empirical formula Get moles of each element & divide each amount by smallest mole ratioo Use molar mass to get “x” Find empirical massPolyatomic IonsNH4+ ammoniumOH- hydroxideCN- cyanideC2H3O2- acetateBrO3- bromateClO3- chlorateMgO3- manganateNO3- nitrateCrO42- chromateCr2O72- dichromatePO43- phosphateSO42- sulfateC2O42- oxalateCO32- carbonate Solve equation: Mm=Emx- Reactions:o Combination: A + B  ABo Decomposition: AB  A + Bo Combustion: hydrocarbon + O2(g)  CO2(g) + H2O(g)- Limiting reactant problems give info about both reactants but must find the producto To find excess convert limiting reactant to 2nd reactant o Of 2nd reactant: initial – final = excess- Efficiency  % yield = actual yieldtheoretical yield∗100Chapter 4 Aqueous Reactions & Molarity- Hydration: H2O molecules break up crystal lattice (solid)o Break solid into molecules (molecular) or ions (electrolytedissociation)- Electrolytes: o Strong (100% dissociation) = strong acids, strong bases, ionic compoundso Weak (partial dissociation) = weak acids and weak baseso Non-electrolytes (no dissociation) = molecular compoundso Ions that are always soluble: NO3-, NH4+, C2H3O2- and alkali metals- Reactions: o Single replacement: A + BX  AX + Bo Double Replacement: AX + BY  AY + BX Precipitation rxn: form insoluble solid Neutralization rxn: Acid + Base  H2O(l) + salt Unstable compound produced and immediately decomposes- Complete ionic equation: break chemicals that are aqueous and strong electrolytes- Predict single replacement reactions with activity series of metalsStrong Acids/Bases: 100% dissociation (eqn uses  one way arrow)Acids BasesHCl, HBr, HI LiOH, NaOH, KOH, RbOH, CsOHHClO4, HClO3, HNO3, H2SO4Ca(OH)2, Sr(OH)2, Ba(OH)2Weak Acids/Bases: partially dissociate (eqn uses ⇌ 2 way arrow)Acids BasesNOT on list of strong acids NH3- Predict double replacement reactions by products; must have solid, liquid, gas (from unstable decomposition) or weak electrolyte - Solution: o Solute = being dissolved, usually smaller amounto Solvent = H2O in aqueous solution, usually larger amounto Dilution: add solvent to concentrated (stock) solution Moles stay the same, volume increases  decrease molarity (M=mol/L) M1V1=M2V2o Titration: info given about both reactants and interested in reactant  As compared to a limiting reactionChapter 5Thermochemistry- calorie: energy needed to raise temperature of 1g of H2O by 1oCo 1 cal = 4.184 J- Calorie: energy from foodo 1 Cal = 1000 cal = 4.184 kJ- q = heato endothermic: gain heat from breaking bond, can be a reactanto exothermic: lose heat by forming bond, can be a product- H = enthalpy, heat in a system at constant pressure- Temperature: o Fahrenheit: water freezes at 32o/ boils at 212oo Celsius: water freezes at 0o/ boils at 100oo Kelvin: absolute zero scale, OK is as cold as it goes- Calorimetry:o Heat capacity, C = amount of heat needed to changetemperature by 1K or 1oCo Molar heat capacity, CM = heat capacity of 1 molo Specific heat capacity, CS = heat capacity of 1g of a substance (J/g*K)o q=CSm T *CS water = 4.184 J/g*Ko Constant pressure calorimetry = “coffee cup”o qrxn = -qsoln- Hess’s law:o Hrxn = sum of each Hrxn in series of reactionso Manipulate individual reactions so correct chemicals are on right side of reaction and have correct coefficient- Standard Heats, Hoo Most stable form of element at STP (298K/25oC and 1atm)TF = 1.8TC + 32TK = TC + 273o HoF = standard heat of formation, heat needed to form 1 mol of a product from elements in natural state (kJ/mol) Element in standard state has HoF = 0- Can use q=-(CSm T) to get kJ/mol Most compounds have -


View Full Document

UB CHE 101 - Exam 1 Study Guide

Documents in this Course
Load more
Download Exam 1 Study Guide
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Exam 1 Study Guide and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Exam 1 Study Guide 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?