2013 HONORS Chemistry Midterm Review  GOOD LUCK! 

This review sheet is a list of topics and sample practice problems only. The practice problems are good representation of what to expect on the midterm, but it is not enough to just study from the review. You need to look over your notes, old review sheets, tests and quizzes, homework, etc. Ask questions!!!! You may check your answers online and I am available Tuesday-Friday for extra help.

Chapter 1 & 2: Intro to Chemistry Key Topics:  What is chemistry  Uncertainty in Measurement –sig figs  Physical and chemical properties  Physical and chemical changes

1. Determine the number of significant figures in the following values: a. 6.70 3 c. 15,300 3 b. 0.03260 4 d. 4.68 3

2. Perform the following calculations and express your answer with the correct number of significant figures: a. 34.0 x 45.62 = 1550 b. 45 – 95.24 = -50.

Chapter 3: Atomic Structure Key Topics:  Models of the atom (Modern atomic theory)  Isotopic Notation, Subatomic particles  Atomic Orbitals – s, p, d shapes  Electron configurations  Valence electrons  Periodic Law

3. Describe the basic structure of the atom in the modern atomic theory (be able to label protons, neutrons, electrons, and the nucleus) (Ch. 3): Protons, neutrons – in nucleus (densely packed) Electrons – surrounding nucleus in orbitals/clouds Protons: + Electrons: - Neutrons: neutral

14 4. protons = 6 neutrons = 8 electrons = 6 6 C

5. Sketch s and p orbitals (Ch 3): Electron clouds where there is a probability of finding electrons

6.

Chapter 4: The Periodic Table Key Topics:  Organization of the Periodic Table (Periodic Law)  Periodic Trends: Electronegativity

7. State the periodic law (Ch 4): Elements are grouped on periodic table by their physical and chemical properties (atomic number increases). “The physical and chemical properties of the elements are periodic functions of their atomic numbers” (pg 116).

8. Label the following areas on your periodic table (some may overlap) (Ch 4):

o

Chapter 5: Ionic Compounds Key Topics:  Octet Rule  Naming and writing formulas  Properties

9. Compare and contrast ionic and covalent bonds (Ch 5 and 6, essay): a.

Ionic Both Covalent

Metal & nonmetal Both form stable octets Nonmetal & nonmetal Giving/taking electrons (8 valence electrons) Sharing of electrons (transferring) Low MP and BP High MP and BP Both do not conduct Poor conductors of Conducts electricity electricity as solids electricity when molten or dissolved in water 10. Name the following ionic formulas (Ch 5):

1. NH4Cl Ammonium chlor ide 2. CaO Calcium oxide 3. NaF Sodium fluor ide

4. Mg(NO3)2 Magnesium nitrate 5.

11. Write formulas for the following ionic compounds (Ch 5): 12.

6. Magnesium Hydroxide Mg(OH)2

7. Strontium Chloride SrCl2

8. Calcium Hydroxide Ca(OH)2

9. Sodium Phosphate Na3PO4

Chapter 6: Covalent Compounds Topics:  Naming and writing formulas  Properties  Lewis Dot structures  Polar vs. Non-polar covalent bonds  VSEPR Be able to…  Sketch lewis structures and predict molecular geometries (VSEPR)

11. Name the following covalent compounds (Ch 6):

a. CO2 Carbon dioxide

b. SiF4 Silicon tetrafluoride

c. SnO4 Tin tetraoxide

d. CCl4 Carbon tetrachloride e.

12. Write formulas for the following covalent compounds (Ch 6):

a. dinitrogen pentoxide N2O5

b. phosphorus trichloride PCl3 c. carbon monoxide CO

d. selenium hexachloride SeCl6

13. 14. Write the dipole moment and bond character of each (Ch 6): a. C-H 2.6-22.2=.4 nonpolar covalent b. C-S 2.6-2.6=0 nonpolar covalent c. Na-Cl 0.9-3.2=2.3 ionic d. Si-O 1.9-3.4=1.5 polar covalent e. Cl-N 3.2-3.0=.2 nonpolar covalent

0.0 – 0.4 Nonpolar Covalent 15. Draw Lewis Structures0.4-1.7 (Ch 6): Polar Covalent > 1.7 Ionic CH3Cl OF2 SO3

Check answers during class.

16. Identify the shape and bond angle of molecular compounds (Ch 6): Lewis Structure Shape Bond angles NH3 Trigonal pyramidal <109.5 SiO2 Linear 180

CH3Cl Tetrahedral 109.5

Chapter 7: Organic Chemistry Topics:  Organic bonding  Hydrocarbons  Alkanes, alkenes, alkynes  Naming and drawing formulas  Functional groups  Practical applications

Organic chemistry vocabulary (Ch 7): 17. Define hydrocarbon: compounds containing carbon and hydrogen atoms

18. Compare/Contrast Alkanes, Alkenes, Alkynes: Type of Bonds Name Alkane Single -ane Alkene Double -ene Alkyne Triple -yne

19. List and describe 3 uses of organic compounds (Ch 7, organic presentations) Soap, perfumes, synthetic fabrics, polymers, medicine, PLASTIC petroleum (energy) 20. Drawing and naming organic structures and naming (Ch 7): Recognize how to draw/name structures for alkanes, alkenes, and alcohols.

3-octene 8 carbons, double bond after C 3. See answer during class.

Pentane 5 carbons, all single bonds. See answer during class.

1-butanol

2-pentene

Chapter 8: The Mole Topics:  Mole  Empirical formulas  Avogadro’s number  Molecular formulas  Percent composition Be able to…  Calculate molar mass  Convert between grams and moles  Convert between number of particles and moles  Perform multi-step conversions  Calculate percent composition  Determine empirical formula  Determine molecular formula

21. Determine the molar mass of the following compounds (Ch 8):

Al2(SO4)3 2(26.98) + 3(32.06) + 12(16.00) = 342.14

KBr 39.10 + 79.90 = 119.00g/mol Li2O 2(6.94) + 16.00 = 29.88g/mol

22. Find the percent composition of each element (Ch 8): %Mg in MgSO4?

Total mass MgSO4: 24.31 + 32.06 + 4(16.00) = 120.37 g/mol Mg: 24.31/120.37 x 100% = 20.20% Mg S: 32.06/120.37 x 100% = 26.63% S O: 64.00/120.37 x 100% = 53.17% O

%H in C2H5O?

Total mass C2H5O: 2(12.01) + 5(1.01) + 16.00 = 45.07 g/mol C: 24.02/45.07x 100% = 53.29% C H: 5.05/45.07x 100% = 1.11% H O: 64.00/45.07x 100% = 35.50% O

23. Mole conversions (Ch 8): # of moles in 2.5g of Aluminum Oxide? 2.5 g x 1 mol = .025mol 101.96g

# of moles in 15g of Neon? 15 g x 1 mol = .74mol 20.18g

# of grams in .5mol of Gold? .5 mol x 196.97g = 98.49g 1mol

# of moles in 1.5mol of Zinc (II) Chloride? 1.5mol x 136.29 = 204.4g 1mol Chapter 9: Chemical Reactions and Equations Key Topics:  Chemical reaction  Coefficient  Reactant  Subscript  Product  State of matter symbols  Chemical equation  Reaction Types  Word equations Be able to…  Write formulas for both ionic and covalent compounds  Identify parts of a chemical equation  Write and balance equations  Identify types of reactions

24. Balancing equations (Ch 9):

4 Fe + 3 O2  2 Fe2O3

3 Fe + 4 H2O  1 Fe3O4 + 4 H2

3 Mg + 1 N2  1 Mg3N2

25. Interpreting chemical equations (Ch 9): C(s) + O2(g)  CO2(g) + 393.5kJ

a. Is this endothermic or exothermic reaction? exothermic b. What are the states of the reactants? solid, gas c. What is the ratio of carbon to carbon dioxide?

1 C: 1 CO2 d. If 5 moles of carbon are used, how many moles of CO2 are made? 5 mol e. If 3 moles of carbon are used, how many moles of CO2 are made? 3 mol f.

Chapter 11: Stoichiometry!!! Topics:  Stoichiometry  Limiting  Percent Yield  Molar ratios reactants Be able to….  Determine molar ratios  Perform mole to mole conversions  Perform mass to mass conversions  Determine limiting reactant  Calculate percent yield

1. How many moles of oxygen are needed to combine with 87g of lithium? 4Li + O2  2Li2O

87 g Li x 1 mol FeCl2 x 1 mol O2 x 32.00g O2 = 100.29 g FeS 6.94 g 4 mol Li 1 mol

2. What mass of FeS must react to form 326g of FeCl2. FeS + 2HCl  H2S + FeCl2

326 g FeCl2 x 1 mol FeCl2 x 1 mol FeS x 87.91g FeS = 226g FeS 126.75 g 1 mol FeCl2 1 mol

10.