Essential oils from the lavender plant are used in aromatherapy - Scottish Highers Chemistry - Question 10 - 2017

The component that is present in lavender oil A and missing in lavender oil B is 1,8-cineole.

First, we calculate the total amount of 1,8-cineole in 500 cm³:

• Concentration = 0.92 mg/cm³
• Total volume = 500 cm³

Total mass of 1,8-cineole:

$\text{Total mass} = 0.92 \text{ mg/cm}^3 \times 500 \text{ cm}^3 = 460 \text{ mg}$

Convert mg to kg:

• 460 mg = 0.460 g = 0.000460 kg

Now, using the cost of 1 kg of 1,8-cineole (£59.10) to find the cost of 0.000460 kg:

Cost of 1,8-cineole:

$\text{Cost} = 0.000460 \text{ kg} \times £59.10 = 0.0271 \text{ pounds}$

Convert to pence:

$0.0271 \text{ pounds} \times 100 = 2.71 \text{ pence}$

In the provided structure of linalool, the chiral carbon is the one that is attached to four different groups. A visual identification in the structure should show the carbon atom with different substituents, which needs to be circled.

The molecular formula of farnesene, which consists of three isoprene units, can be written as C₁₅H₂₄ or C₅H₈ depending on the structure representation.