The Nature Of Solubility

1. The Nature Of Solubility 8/8/2014 3

2. Today’s Warm-Up 1 • Looks look at a cool “super-saturated” solution of sodium acetate and water • The slightest little touch or impurity causes it to begin crystallization- turning from a liquid to an exothermic crystal “ice”

3. Today’s Warm-Up 2 Complete text assignment from last week Let’s grade our homework sheets Nuclear reactions Test Review Solutions

4. Today’s Objectives Grade and graph 2nd six-weeks tests Grade Lab notebooks Solutions/Solubility vocabulary Unwrapped Activity Solubility Lab #1 Factors that affect solubility Solubility curves Solubility Lab #2

5. Grade Test and Homework • A • G • C • G • B • H • A • J • B • F A H C J B H D F B F • A • G • D • Each “X” is 3.3 pts each • Timetograph! • A • H • B • J • B • F • C • H • C • J

6. Lab Notebook Check • You are looking for: • Notebook covered and decorated (if not, it’s an automatic “1”) • Table of contents up-to-date (End Products) • Notes neat and up-to-date • At least two “Mustang Science Approved” stamps this grading period • Must have Cornell Notes summaries for a “3” • Remember: 3=WOW! 2=Good 1=Needs work 0= • Draw line in table of contents to show 3rd 6-weeks

7. Solubility and Solutions Questions Vocabulary words Formulas Main Ideas Possible Test Questions Key Concepts Notes Notes Notes Notes Notes Notes Notes Notes Notes Notes Summary of the notes and information learned

8. Vocabulary List these 5 vocabulary terms in the left column of your Cornell Notes Solubility Solvent Solute Solubility curve

9. Solutions- not “answers”… mixtures! • Solution: a mixture of two or more substance- homogeneous at the molecular level • Can be solid- an alloy like 14K gold • Can be liquid- carbonated water • Can be gas- the air you breathe • Solvent: present in greatest amount • Solute: the smaller amount/component • When a solute is evenly distributed throughout the solvent we say it is dissolved.

10. Unwrapping Solubility Contest • Students groups of three • Use stopwatch to time your group • Carefully unwrap each layer of foil until you reveal a marble; no ripping apart or tearing foil! • Stack each layer of foil as you unwrap • Record final time and number of foil layers

11. Solubility Lab #1 • Solubility rate and particle size • Work w/lab partner- groups of two • Amount (mass) of all types of sugar must be equal • Must crush granular sugar for powdered sample • Dissolve and measure one type of sugar at a time • Do NOT shake, stir or try to influence the rate of dissolution • What controlled variable might skew our results?

12. Dissolving Rate • I love sweet iced tea. It bums me out when a restaurant has only unsweet… • Sugar doesn’t dissolve well in cold tea! • What are some factorsthat affect the dissolvingrate of sugar in tea???

13. Dissolving Rate • Stir! Stir! Stir! (molecular motion) • Finely ground sugar instead of cubes (greater surface area) • Heat- warm tea vs cold (molecular motion again)

14. Solubility • So, what happens to the sugar molecules when they dissolve? • What happens if I keep adding sugar to my glass of tea? • Solubility: the amount of solute that can be dissolved in a volume of solvent under certainconditions • What is a substance that will NOTdissolve called?

15. Solubility • For solids, solubility normally increases with increasing temperature. • For gases, the opposite occurs.Solubility decreases with increasingtemperature. (Which spews more,a cold soda or a warm one?)

16. Solubility Curves What are Solubility Curves? Solubility is the amount (in grams) of a soluble compound that will dissolve in a set amount of water (normally 100 grams). This value is different for different temperatures. A solubility curve is a graph of the solubility of a compound (grams/100 grams water on the Y axis) at various temperatures (Celsius on X Axis). Each compound has a different curve.

17. Solubility Curves What are Solubility Curves?

18. Solubility • Solubility is a two-way street, at anytime in a solution you may have molecules falling in and out of solution… When the number of solute molecules falling in and out of solution are equal we have reached equilibrium. • Unsaturated • Saturated • Supersaturated

19. Solubility Lab #2 • Solubility rate and temperature • Work w/lab partner- groups of two • Amount (mass) of all types of sugar must be equal • Dissolve and measure one type of sugar at a time • Do NOT shake, stir or try to influence the rate of dissolution • What TWO variables are in play in this set of experiments?

20. Solubility Lab Data Analysis Complete the questions and graphs associated with the lab results from last class period. Use the first lab as our “cold” results for lab #2 as well (tap water temperature of 18 degrees C). If your partner is gone you may work with another classmate (each on your own data though).

21. Water- Homework Next subject- water, solubility, electrolytes, ionic solutions, pH… BrainPop Homework sheet

22. Solubility and Solutions Questions Vocabulary words Formulas Main Ideas Possible Test Questions Key Concepts Notes Notes Notes Notes Notes Notes Notes Notes Notes Notes Summary of the notes and information learned

23. Make it a great day Mustangs!