Calculate the Internal Energy Change, Δ_rU, for the Combustion of 29.3

question 62

Multiple Choice

Calculate the internal energy change, Δ_rU, for the combustion of 29.3 g of vitamin C (C₆H₈O₆, molar mass = 176.124 g mol^-1) if the combustion inside a bomb calorimeter, C_cal = 8.31 kJ °C^-1, causes a temperature change from 21.5 °C to 68.3 °C.

• A) -1.78 × 10³ kJ mol^-1
• B) -2.34 × 10³ kJ mol^-1
• C) -6.03 × 10³ kJ mol^-1
• D) -9.19 × 10² kJ mol^-1
• E) -1.67 × 10² kJ mol^-1

Apply statistics to ensure confidence in standard time calculations based on observed times and standard deviations.

Determine the financial implications of performance against standard times in incentive programs.

Estimate required sample sizes for time studies to achieve desired confidence levels and errors.

Appreciate the importance of accurate element descriptions and their impact on time measurement accuracy.

---

Definitions:

Vigorous Exercise

Physical activity that is intense enough to significantly increase heart rate and respiratory rate, burning more calories and strengthening the cardiovascular system more than moderate exercise.

Severe Migraine Headaches

Intense and painful headaches often accompanied by nausea, vomiting, and sensitivity to light or sound, classified as migraines can significantly disrupt daily life.

GABA

Gamma-Aminobutyric Acid, an inhibitory neurotransmitter in the central nervous system that helps regulate neuronal excitability throughout the nervous system.

Serotonin

A chemical messenger in the brain crucial for maintaining stable mood, as well as promoting feelings of contentment and joy.