Explore Westonci.ca, the leading Q&A site where experts provide accurate and helpful answers to all your questions. Join our platform to get reliable answers to your questions from a knowledgeable community of experts. Experience the ease of finding precise answers to your questions from a knowledgeable community of experts.
Sagot :
Answer:
-694.8 kJ/mol ≅ -695 kJ
Explanation:
The enthalpy of combustion (ΔHc) is defined as the amount of heat that is released when 1 mol of the compound is burned. We have the mass of methanol (0.14 g) and we have to calculate the moles present in that mass. For that, we need the molecular weight of methanol, which is calculated from the molar mass of the chemical elements.
Methanol: CH₃OH
Mw(CH₃OH) = (12 g/mol x 1 C) + (1 g/mol x 3 H) + 16 g/mol O + 1 g/mol H = 32 g/mol
moles of CH₃OH = mass/Mw(CH₃OH) = 0.14 g/(32 g/mol) = 4.4 x 10⁻³ mol
As the heat is released, the change in enthalpy is a negative value: -3.04 kJ.
Finally, we divide the released heat (-3.04 kJ) into the number of moles of CH₃OH:
ΔHc= (-3.04 kJ)/(4.4 x 10⁻³ mol CH₃OH) = -694.8 kJ/mol ≅ -695 kJ
We appreciate your time. Please revisit us for more reliable answers to any questions you may have. Thanks for using our service. We're always here to provide accurate and up-to-date answers to all your queries. Westonci.ca is here to provide the answers you seek. Return often for more expert solutions.