Apchem frq

Aluminum a

24J/mol K x 1 mol x 635 K = 15kJ

15kJ + 10.7 kJ = 25.7 kJ

Aluminum b

1675kJ/mol x 1 mol/2 mol Al = 837.5 kJ

Recycling takes less energy

Beaker of sand a

241 kJ

Beaker of sand b

Subtract masses and get 7.06g

7.06 g x 1 mol/58.12 g = 0.121 mol

Beaker of sand c

0.121 mols x -2659 kJ/1 mol = -322 kJ released

Beaker of sand d

Yes the my answers support the students claim because the theortical yield from part c should be equal to the actual yield from a, however the yield of part a was less than the yield of part c

Combustion of c2h4 a

-1412kJ/mol

Energy diagram

Products lower than and delta h is the distance between reactants and products

C2h5oh + 3o2

42 kJ/mol

Bond enthalpies table with missing value d

358 kJ/mol

Predict sign for delta s

Negative bc more moles of gas on reactants which means higher entropy within reactants.