A student is measuring the boiling point of some liquids using the experimental setup shown below:
She measures the boiling point of water, propanol, and cyclohexane.
a.[2]
The student's method is not safe. Explain why it is not safe and explain how she could improve her method to make it safer.
b.
[2]
The student looks up some data on the melting points and boiling points of some hydrocarbons:
| Substance | Formula | Melting point (∘C^{\circ}\text{C}∘C) | Boiling point (∘C^{\circ}\text{C}∘C) | State at 25 ∘C25\ ^{\circ}\text{C}25 ∘C |
|---|---|---|---|---|
| Butane | C4H10\text{C}_4\text{H}_{10}C4H10 | −138-138−138 | −1-1−1 | ……………………\dots\dots\dots\dots\dots\dots\dots\dots…………………… |
| Pentane | C5H12\text{C}_5\text{H}_{12}C5H12 | −130-130−130 | 363636 | ……………………\dots\dots\dots\dots\dots\dots\dots\dots…………………… |
| Docosane | C22H46\text{C}_{22}\text{H}_{46}C22H46 | 444444 | 369369369 | Solid |
Complete the table to show the states of butane and pentane at 25 ∘C25\ ^{\circ}\text{C}25 ∘C.
c.[2]
Pentane burns in oxygen, O2\text{O}_2O2. Carbon dioxide and water are made. Write a balanced symbol equation for this reaction.