Marking Period 3 Review

Day 3Unit 9, Mole Calculations

Unit 10, Solutions

Schedule For the WeekDay 1: Unit 7 - PE Diagrams and Equilibrium(Wednesday)

Day 2: Unit 8 - Heat/Exo and Endo Reactions(Thursday)

Day 3: Unit 9 - Mole Calculations and Unit 10 - Solutions(Friday)

Day 4: Marking Period 3 Review Exam(Monday)

How are you graded?

• The packets for Day 1, 2, and 3 are worth 25 HW points each.

• The exam on Monday is an exam grade. • On days 1, 2, and 3, the class will end with a

short quiz on that day’s material. • The class with the highest quiz average

receives a reward the following day.

Answer key to day #2

• Topic #1: summarize1) Did during Do-Now…KE change = temp change; PE change = phase changea) MP = Liquid to solid = 50°C; BP = gas to liquid = 110°Cb) KE decreases = AB, CD and EFc) PE decreases = BC and DEd) B

• Topic #2: entropy1. S L randomness increases (particles spread out)2. L S entropy decreases (particles closer together)Summarize: 1) EntRopy = Randomness

• Topic #3: enthalpy1. enthalpy increases (energy a product = adding heat l gSummarize: 1) EntHalpy = Heat

Unit 8 practice

1) 3 minutes2) 5 minutes3) B4) 110°C5) C6) 20 kJ7) 15 kJ

Heat calc review

More practice!

1) Mcdt = 15 x 4.18 x 8 = 501.6 J2) mHf = 14.2 x 334 = 4742.8 J3) mHv = 8.2 x 2260 = 18532 J4) Mcdt = 109 gNot water5) Mcdt = 27762.8 J6) mHf = 3185.5 J7) mHv = 4956.7 J8) Mcdt = 0.266 g

1. If Daniel dissolves 20g NaCl at 90C in 100g H2O, is his solution saturated, unsaturated, or supersaturated? _____________________________ Explain: 2. If Laura dissolves 20g NaCl at 90C in 100g H2O, how many more grams does he need to dissolve to make a saturated solution? _________________ g 3. Jaylene added 70 grams HCl to 100grams H2O at 70C. How many grams of solid precipitate settled at the bottom of the container? _______________ g 4. Chris completely dissolved 100g KNO3 in 100g H2O at 70C. When the solution cooled to 10C, how many grams of KNO3

precipitated out of the solution (became a solid and sat at the bottom of the beaker) _____________ g 5. At 10C, how many grams of SO2 dissolves in….a) 100 grams of H2O ___________ gb) 200 grams of H2O ___________ gc) 50 grams of H2O ___________ g

Practice: 1. Which molecule is polar? (a) H2 (b) CH4

(c) H2O (d) Br2

2. Which molecule is polar? (a) Cl2 (b) I2

(c) CO2 (d) NH3

3. Which molecule is non-polar? (a) HCl (b) H2O(c) F2 (d) CH4

4a. Explain, in terms of distribution of electrons, why H-H is non-polar. Answer: H-H is a polar bond because the atoms have equal electronegativities so the electrons are shared equally. 4b. Explain, in terms of distribution of electrons, why H-F is polar.

5a. Explain, in terms of electronegativity, why H-H is non-polar. Answer: H-H is a non-polar bond because both H atoms have the same electronegativity. 5b. Explain, in terms of electronegativity, why H-F is polar. 6. Explain, in terms of molecular polarity, why oils do not dissolve in water. (Your answer must include the polarity of both water and oil to receive credit) 7. An atom of which element has the weakest attraction for electrons in a covalent bond?(a)F (b) O(c) Na (d) Cl