Virtual Lab: Can Properties Determine Bonding?

Pre-Lab Research

For each of the six substances used at Station 1, look up the chemical formula, classify the type of bonding, and record the melting point. Use a reliable reference (PubChem, your textbook, etc).

Solvent Bonding Types

Each of the six solids will be dissolved in these three liquids at Station 1. Identify the type of bonding present in each solvent.

Station 1 — Solubility, Conductivity & Magnetism

Photos below show each solid under magnification, and each solid after being mixed into water, hexanes, and ethanol (left to right in each vial photo, following the label). Record what you observe, then use the virtual instruments to test conductivity and magnetism — just like using a real conductivity probe and magnet at the station.

Station 2 — Reactivity Testing

For each solid, run the virtual reactivity test: a scoop of solid is mixed with water + universal indicator, then separate scoops are tested with HCl and NaOH. Click each button to reveal the result, exactly as if you had performed the test yourself.

Station 3 — Card Sort

Using everything you learned at Stations 1 & 2, sort each unknown substance below into a bonding category based on its properties. Choose a category for every card, then check your work.

Station 3 Questions

1) Which properties were the most useful in classifying the type of bonding?

2) If a substance is known to dissolve in water and the resulting solution conducts electricity, what type of bonding must be present?

3a) Which category (or categories) of substances are attracted to a magnet?

3b) Are all substances in that category attracted to a magnet?

4) What generalizations (regarding properties) can be made for each type of bonding? (nonpolar covalent, polar covalent, ionic, metallic)

Post-Lab Reflection

Use your data from Stations 1–3 to answer.

Summarize the property trends you observed for each bonding type (melting point, solubility pattern, conductivity, magnetism).

If you were given an unknown solid tomorrow, what three tests would you run first, and why?

Graphite and silicon didn't fit neatly into any one category. What property made them tricky to classify, and what type of bonding do you think best explains their very high melting points?

AP FRQ Practice — Turpentine & Linalool

Turpentine, C₁₀H₁₆, is a substance that can be obtained by distilling the resin of pine trees. It can be used as a solvent for thinning some types of paints, but it is also used in the manufacture of some fragrant chemical compounds.

The solubility of turpentine is 20.0 mg/L in water.

a) Calculate the molarity of turpentine in a saturated aqueous solution. The molar mass is 136.238 g/mole.

b) Would turpentine have a higher solubility in ethanol (C₂H₅OH) or hexanes (C₆H₁₄)? Justify your selection.

One chemical manufactured from turpentine is linalool, C₁₀H₁₈O (3,7-dimethylocta-1,6-dien-3-ol). Linalool is used as a scent in a large percentage of perfumed products such as cleaning products, soaps, shampoos and lotions. An approximate skeletal structure is shown below.

(Skeletal outline — dimethyl branch points, terminal vinyl group, and internal alkene are shown; not to scale.)

c) How many pi bonds are present in the linalool structure?

d) What is the bond angle predicted for the C–O–H bond?

e) Calculate the molar mass of linalool, C₁₀H₁₈O.

f) The solubility of linalool in water is 1.59 g/L. Calculate the molarity of a saturated aqueous solution. (Assume no volume change when linalool is added.)

g) Explain why linalool is more soluble in water than turpentine is in water. (Reference the intermolecular forces present in each substance.)

h-i) Linalool can also be extracted from lavender oil; it makes up 35.0% of the mass of a sample. If a 25.0 g sample of lavender oil is treated to extract the linalool, what is the theoretical yield of linalool in moles? (Use the molar mass from part e.)

h-ii) If the actual amount of linalool extracted was 0.0505 moles, what was the percent yield for this experiment?

Review & Submit

This compiles everything you've entered into one block of text so you can paste it into a Google Doc and submit it, the same way you'd submit a normal lab.

Click "Build Summary" to generate your report.