Activity 5Activity 5

Follow-up Follow-up

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 LiquidsActivity 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

Titles: Identifying Liquids & Identifying Solids

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

Test Liquid A Liquid B

Appearance    

Miscible in water    

Miscible in ethanol    

Contains water    

Corrosive    

Toxic    

Properties of Separated Solids

Test Red tube Black square Red squareLight grey cylinder

Dark grey cylinder

Electrical conductivity          

Density relative to water          

Density relative to ethanol          

Reacts with copper chloride  none  none  none  reacts  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 <3 or >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/cm3 at standard temperature and pressure.

• Ethanol has a density of 0.79 g/cm3

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 don’t understand the instructions