Presentation on theme: "Activity 5 Follow-up. 2. What safety precautions did you take while working with the unidentified mixture? Goggles and gloves (tie hair back) Avoid direct."— Presentation transcript:
2. What safety precautions did you take while working with the unidentified mixture? Goggles and gloves (tie hair back) Avoid direct contact with the substances by using forceps and droppers Keep hands away from face Thoroughly cleaned all equipment Treat substance as hazardous Make sure to properly label the substance and keep the lid tightly closed Wash hands
3. How would you separate: b. salt and iron shavings Magnet Sieve Dissolve salt in water c.salt and sand Add water
Activity 6 – Identifying Liquids Activity 7 – Identifying Solids Today you will be doing two activities at once. Students will perform tests to identify physical and chemical properties of the isolated liquids and solids from Activity 5. Testing results will provide evidence to assist in the identification of the materials isolated from the unlabeled mixture.
Key Terms These characteristics are inherent for specific materials (amount does not matter). Conductivity –Ability of a substance to transmit electricity –Pine wood is not conductive, but tin is Density –Mass- per-unit volume of a substance –Density of a kg of tin is greater than a kg of pine Reactivity –ability of a substance to react chemically with another substance –Tin reacts chemically with copper chloride solution, but pine does not
Problem: What are the liquids and the solids in the mixture? Initial Thoughts/Hypothesis: Based on your observations so far, you can make an educated guess on what they might be
Procedure You will perform a series of tests to help identify the liquids & soldids separated in Activity 5. The tests will determine the chemical and physical properties of the liquids. Liquid A is the clear oily liquid Liquid B is the orange liquid Add these labels under Name on your Chemical Data Sheets for each of the two liquids.
E Data/Observation: Properties of Separated Liquids TestLiquid ALiquid B Appearance Miscible in water Miscible in ethanol Contains water Corrosive Toxic Properties of Separated Solids TestRed tubeBlack squareRed square Light grey cylinder Dark grey cylinder Electrical conductivity Density relative to water Density relative to ethanol Reacts with copper chloride none reacts
Tests Appearance Color state (solid, liquid, gas) Transparency thickness Miscible in water and ethanol Mixes = Miscible Does Not Mix = Not Miscible Contains Water Pink = water Blue = no water Corrosive pH 11 = corrosive pH 3-11 = not corrosive Toxic Red = toxic Use Table 2: Information on Selected Liquids on A- 25 to identify the two liquids
Density If I place these in a cup of water, will they sink or float? If a solid, liquid, or gas floats in something else, it is relatively less dense. If it sinks, it is more dense. Pure water has a density of 1.0 g/cm 3 at standard temperature and pressure. Ethanol has a density of 0.79 g/cm 3
Tests Electrical Conductivity –No light = does not conduct –Light = conducts electricity Density Relative to Water –Sinks = more dense –Floats = less dense Density Relative to Ethanol –Sinks = more dense –Floats = less dense Reacts with Copper Chloride –Reaction = color change, bubbling, cloudiness, temperature change, or the formation of a precipitate (solid)
Procedure Follow the instructions at each station Make sure you leave the equipment and materials just as you found them Ask for clarification if you dont understand the instructions