Question

The ΔHcomb value for anethole is -5539 kJ/mol. Assume 0.840 g of anethole is combusted in a calorimeter whose heat capacity (Calorimeter) is 6.60 kJ/°C at 20.6 °C. What is the final temperature of the calorimeter

Answer 1

Answer:

Final temperature of calorimeter is 25.36^{0}\textrm{C}

Explanation:

Molar mass of anethole = 148.2 g/mol

So, 0.840 g of anethole = $\frac{0.840}{148.2}moles$ of anethole = 0.00567 moles of anethole

1 mol of anethole releases 5539 kJ of heat upon combustion

So, 0.00567 moles of anethole release $(5539\times 0.00567)kJ$ of heat or 31.41 kJ of heat

6.60 kJ of heat increases $1^{0}\textrm{C}$ temperature of calorimeter.

So, 31.41 kJ of heat increases $(\frac{1}{6.60}\times 31.41)^{0}\textrm{C}$ or $4.76^{0}\textrm{C}$ temperature of calorimeter

So, the final temperature of calorimeter = $(20.6+4.76)^{0}\textrm{C}=25.36^{0}\textrm{C}$