Styrene, C₈H₈, Is One of the Substances Used in the Production

question 59

Multiple Choice

Styrene, C₈H₈, is one of the substances used in the production of synthetic rubber. When styrene burns in oxygen to form carbon dioxide and liquid water under standard-state conditions at 25°C, 42.62 kJ are released per gram of styrene. Find the standard enthalpy of formation of styrene at 25°C. (Given: $\Delta$ H°_f[CO₂(g) ] = -393.5 kJ/mol, $\Delta$ H°_f[H₂O(l) ] = -285.8 kJ/mol, $\Delta$ H°_f[H₂O(g) ] = -241.8 kJ/mol)

• A)323.8 kJ/mol
• B)~4249 kJ/mol
• C)~8730 kJ/mol
• D)~636.7 kJ/mol
• E)147.8 kJ/mol

---

Definitions:

Vocalizations

The sounds produced by the vocal cords, including speech, cries, or other vocal output.

Infant

A young child in the earliest period of life, especially from birth to one year old.

Classical Conditioning

A training method where two different stimuli are paired repeatedly, leading to a response initially triggered by the second stimulus being ultimately triggered by the first stimulus alone.

Laughing

The act or sound of expressing mirth, joy, or amusement through vocal chuckles or guffaws.