Chemisty question?

Hess’s Law. (Question 6.58)

Combustion reactions involve reacting a substance with oxygen. When compounds containing carbon and hydrogen are combusted, carbon dioxide and water are the products. Using the enthalpies of combustion for C4H4 (-2341 kJ.mol), C4H8 (-2755 kJ/mol), and H2 (-286 kJ/mol), calculate ΔH for the reaction

C4H4(g) + 2H2(g) C4H8(g) ΔH =_______kJ

Answer:
you do products-reactants, but remember to multiply the # of mols in the equation

[ (1 mol C4H8)(-2755 kj/mol)] - [(1 mol C4H4)(-2341 kj/mol) + (2 mol H2)(-286 kj/mol)]

this reduces to:
[-2755] - [-2341 + -572]
[-2755] - [-2913]=

158 kJ

The answers post by the user, for information only, FunQA.com does not guarantee the right.



More Questions and Answers:
  • Perform the following conversions?
  • Can XRD determine the molecular formula/ moleculare configuration of a metallic medicine?
  • When ice is reverted to a liquid state, does its volume change?
  • Calculate the number of moles of oxygen produced when 6.75 mol of manganese dioxide decomposes to Mn3O2 + O2:?
  • What kind of pills have the numbers 93 089?
  • When the distillers made ethanol for consumption, why specifically could there be no iron present ?
  • Define the compressibility factor (Z) from (a) van der Waals equation and (b) Berthelot equation?
  • What 1/2 reaction would be reduced by Cr(NO3)3 being reduced by 3 electrons?
  • What is the product and structure of the complex when iron ammonium sulphate react with salicylic acid?