Standard enthalpies of formation at 25 °C are given below

CHEMISTRY · Subjective · A Level · Chemistry · Energetics · Energetics

Problem

Standard enthalpies of formation at 25 °C are given below. C

_4

_{10}

(g) ΔH

_f^{°}

= −125.6 kJ mol

^{-1}

_2

(g) ΔH

_f^{°}

= −393.5 kJ mol

^{-1}

_2

O(l) ΔH

_f^{°}

= −285.8 kJ mol

^{-1}

_2

(g) ΔH

_f^{°}

= 0 kJ mol

^{-1}

(a) Write the balanced equation for complete combustion of gaseous butane, C

_4

_{10}

(g), forming CO

_2

(g) and H

_2

O(l). (b) Using the data above, calculate ΔH (in kJ) for the balanced combustion reaction. (c) Determine the heat (in kJ) released when 10.0 g of C

_4

_{10}

(g) is completely combusted at 25 °C.