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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: matthew on May 29, 2004, 05:18:08 PM

Title: Energy & Disorder
Post by: matthew on May 29, 2004, 05:18:08 PM

I have four questions that I really am not sure how to do.  I'll show what I have done so far....

1.  How much energy would one mole of HCl require to decompose?
    1 mol= ?/HCl2

2.  What is the entropy change for 4Al(cr) + 3O₂ ---> 2Al₂O₃?
    205.138 + 615.414 = about 728 J/K

3.  What is the free energy change for the following reaction?
      HBr(g) + NH₃(g)  -----> NH₄Br

4.  If 10 grams of the sugar C₁₂H₂₂O₁₁ burned in a calorimeter and produced a 5.5 degree C temperature change in 1500 grams of water, what would be the heat of combustion of 1 mole of sugar?

thank you sooo much!

Title: Re:Energy & Disorder
Post by: Donaldson Tan on June 03, 2004, 10:33:58 PM

1. Check your data booklet for the bond dissociation energy for H-Cl

4. Convert 10g to no. of moles. Translate the raise in temperature to heat given out using Q = mc(dT).