Answer to Question #230220 in General Chemistry for eshesh

Question

When one mole of caffeine (C₈H₁₀N₄O₂) is burned in air, 4.96 × 10³ kJ of heat is evolved. Five grams of caffeine is burned in a bomb calorimeter. The temperature is observed to increase by 11.37°C. What is the heat capacity of the calorimeter in J/°C?

Answer 1

It is given that burning one mole of caffeine gives heat.

The given mass of caffeine is 5g.

Molar mass of caffeine can be calculated as shown below.

Calculate the number of moles of caffeine burned as follows:

Q = mc ΔT

0.0258 ×4.96 × 10³ × 284.37

= 3.64 × 10⁴J/°C