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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: viet on October 14, 2008, 11:03:38 AM

Title: Enthalpy/Thermochemical Stoichiometry
Post by: viet on October 14, 2008, 11:03:38 AM

Quote

Consider the following thermochemical equation for the combustion of acetone C₃H₆O the main ingredient in nail polish remover.
C₃H₆O (l) + 4O₂ (g) => 3CO₂ (g) + 3H₂O (g)    /\H_rxn = -1790 kJ

If a bottle of nail polish remover contains 176 mL of acetone, how much heat would be released by its complete combustion? The density of acetone is 0.788 g/mL.

|/\H| = ?

i tried solving this by doing:
176mL (0.788g/mL) = 138.688g

138.688g C₃H₆O (1 mol C₃H₆O / 58.081g C₃H₆O) (-1790kJ / 1 mol C₃H₆O) = -4507.026 kJ

the answer i got is wrong, can someone help?

Title: Re: Enthalpy/Thermochemical Stoichiometry
Post by: Astrokel on October 14, 2008, 11:21:23 AM

hey viet,

Quote

138.688g C3H6O (1 mol C3H6O / 58.081g C3H6O) (-1790kJ / 1 mol C3H6O) = -4507.026 kJ

i got a different value from your working..

Title: Re: Enthalpy/Thermochemical Stoichiometry
Post by: viet on October 14, 2008, 12:51:18 PM

thanks for replying Astrokel, i seem to did the calculation wrong. thanks  :D