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 C_{3 }H_{7 }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 (NO_{3 - }) 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 ∆H

_{Rx }(to dissolve 1 mole of NH_{4 }NO_{3 }in water)c. Based upon the above experimental data, determine Δ H

_{f }(NO_{3 - }).

4. Using thermodynamics, determine the boiling point of butane (C_{4 }H_{10 }) [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. C_{2 }H_{6 (g) }+ O_{2 (g) }--> CO_{2 (g) }+ H_{2 }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]