Ch. 5, 19, 8.9, 11.4 thermodynamics [100 points] AP Chemistry
For problems involving calculations, show your work in an organized manner, include any relevant equation (or formula and conversion factor(s)), put the proper units in your calculations / answer, and have the proper number of significant figures in your answer.
1. How much heat would be generated by the combustion of 1.5 grams of C3 H7 OH ? [20 points]
2. heating curve.
Ethanol (i.e. alcohol with an ethyl group)
ΔHfusion = 109 J / g boiling point = 78 °C
ΔHvaporization = 35.3 kJ / mole melting point = - 114 °CSpecific heat (J / (g K))
liquid = 2.44
gas = 1.4
solid = 0.97
Based on the above information, calculate the amount of heat (in kJ) to change 5.0 grams of ethanol at – 25 °C to 100 °C ? [20 points]
3. Determine Δ Hf (NO3 - ) based on the following (hypothetical) experimental results. The initial and final temperature of water was 21.0 and 15.0 °C, respectively after dissolving 2.0 grams of solid ammonium nitrate in 50.0 mL of water. The specific heat of water is 4.18 J / g K. [20 points]
a. write the chemical equation that describes this reaction.b. Based upon the above experimental data, determine ∆HRx (to dissolve 1 mole of NH4 NO3 in water)
c. Based upon the above experimental data, determine Δ Hf (NO3 - ).
4. Using thermodynamics, determine the boiling point of butane (C4 H10 ) [assume ∆H, ∆S, & ∆G are independent of temperature; 15 points]
5. Determine ∆S (i.e. zero, positive, negative, or ambiguous) of the following reactions; rationalize your answer without calculating its value. [10 points]
a. C2 H6 (g) + O2 (g) --> CO2 (g) + H2 O (g)b. dissolve solid ammonium nitrate in water.
6. Would (liquid) hydrogen peroxide spontaneously decompose to form oxygen gas and water (liquid) ? Justify your response using thermodynamics. [10 points]
7. Define the term, specific heat. [5 points]