Take out write up from yesterday HW: Analysis #1 is due Friday Vocabulary quiz on activities C30 through 35 Thursday Do Now for 2/12/13

C-35 Mystery Liquids Today’s Target: I will be able to use a liquids properties to identify it. Introduce Lab safety Gather data Clean up Analysis 1

C-35 Mystery Liquids How would you describe the contents of these containers? Observations – Noting a fact. Qualitative Observations – Characteristics that can be perceived without making measurements. Ex. Color Quantitative Observations – Measurements/numerical data. Ex. Mass, density, volume, etc.

C-35 Mystery Liquids Read the background and challenge on page C-29 Particles – atoms or molecules that make up substances around us. Different phases of matter In a phase change (solid to liquid, etc.) the basic particles are still the same so it’s considered a physical change. How should we find out what the two liquids are?

C-35 Mystery Liquids Take out student sheet 35.1 from your packet.student sheet 35.1 Lab Safety and tips Goggles and aprons. No Eating or drinking in lab DO NOT TASTE THE LIQUIDS WASH HANDS AFTER STEP 3 IN PART A I will help you with the last 3 rows on Table 1. Rinse out the graduated cylinders after each use. Make sure the balance is set to 0 each time you use it. For Calculating Density, use the following volumes: Group 1 – 6 mlGroup 2 – 8 ml Group 3 – 10 ml Group 4 – 4 ml Group 5 – 8 mlGroup ml Stop AFTER Step 7 Empty liquids down the sink. WASH HANDS!!

Do Now for 2/13/13 Take out C35 HW: Analysis #1 is due Friday Vocabulary quiz on C30 through 35 tomorrow

C-35 Mystery Liquids Today’s Target: I will be able to use a liquids properties to identify it.liquids properties Check HW Review data data Boiling and melting points Analysis 1 through 6 on pages C-32 and 33

Sample Data PropertyLiquid ALiquid B AppearanceClear, colorlessclear, colorless SmellNoneMedicine-like, sharp Feel on fingersWet; about like waterWet, cool, slippery Behavior of a drop on plastic The drop is round and can be moved. The drop is flat and smears when we try to move it. EvaporationThe drop shrank and remained round. The drop shrank and became flatter, and appeared to evaporate faster. Possible identities Density0.98–1.02 g/ml0.75–0.83 g/ml Boiling point97–103°C75–81°C Melting point-2–+2°C ⁰C Possible identities

Sample Data – Cont. Liquid ALiquid B Volume of liquid sample10 ml Mass of graduated cylinder8.0 g7.8 g Mass of cylinder + liquid18.0 g15.9 g Mass of liquid sample10 g8.1 g Density of liquid10.0g/10.0ml = 1.0g/ml8.1g/10ml = 0.81g/ml

C-35 Mystery Liquids Complete analysis 1 through 6 on pages C-32 and 33. Analysis #6 is wrong in the on-line edition!!! Add the word “Phase” to list 1 In #6 part A, change the word from ‘phase’ to ‘phrase’ Expanded answer for #1 is due Friday!!

C-35 Mystery Liquids #1 – Will be turned in on a separate sheet of paper Friday. Make sure you answer all parts of the question completely. A – What you think. B – What evidence you have to support your point of view. C – How you know it’s not one of the other liquids in the table.

C-35 Mystery Liquids 2a. What properties and measurements were most helpful in identifying the two liquids? 2b. Explain your answer. Density and boiling point – Why? All the properties we observed and measured could be used to tell the two substances apart., the density and boiling point were most helpful because they are most exact. 3a. Which of the two liquids was more cohesive? 3b. Explain the observations that support your answer. Liquid A – What observations did you make to support this?

C-35 Mystery Liquids 4. Why should you keep liquid samples capped or covered while studying them? Liquid samples can spill and spread out all over the table. They also might evaporate out of the bottle and are more likely to spread fumes than a solid is. 5. Which would you predict would evaporate more quickly at room temperature: methanol or acetone? Explain why. Acetone. It has a lower boiling point, which means it turns from liquid to gas easier, so it would probably evaporate faster at a lower temperature. We saw this in the activity, with water and the alcohol.

C35 Mystery Liquids #6 – See textbook page C-33

Do Now for 2/14/13 Study for quiz Quiz Go over analysis 1 through 6 Expanded answer for #1 Read and write up C36 Return Work HW: Expanded answer for #1 due tomorrow