Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

| How much heat is required to raise the temperature of 1.50 g of water from 25

ID: 555330 • Letter: #

Question

| How much heat is required to raise the temperature of 1.50 g of water from 25 to 100 °C? 2. The propane fuel (CsHs) used in gas barbeques burn according to the thermochemical equation CsHs(g) + 5O2(g) 3CO2(g) + 4H20(g) dH=-2217k) How much heat would be released by the combustion of 155.5 g of propane? When 1 mole of a gas fuel is burned at constant pressure, it produces (releases) 3452 kJ heat and does 11 kJ of work. 3. a) What are the values of the E and AH for the combustion of the fuel? b) Is the combustion of the fuel in (a) an exothermic or endothermic process? Consider the reaction: CH4(g) + 202(g) CO2(g) + 21120(1) How many grams of methane (CHo) must be burned to produce (release) 267 kJ of heat? 4. AH =-890 kJ 5. When 0.514 g biphenyl (Ci2Hio) undergoes combustion in a bomb calorimeter, the temperature rises from 25.8 °C to 29.4 °C. The heat capacity of the calorimeter is 5.86 kJ/C. Calculate: a) qnn per mole of biphenyl for the combustion process b) qpn per gram of biphenyl for the combustion process 6. Zinc metal reacts with hydrochloric acid according to the following balanced equation: Zn(s) + 2HCl(aq) ZnCl2(aq) + H2(g) When 0.103 g of zinc is reacted with 50.0 g of HCI solution in a coffee-cup calorimeter, the temperature rose from 22.5°C to 23.7 °C, Assume that the specific heat of the solution is the same as that of pure water, 4.18 J/g °C. Calculate: a) Hrn per mol of zinc for this reaction b) Inn per gram of zinc for this reaction s: 7. Using the following reactions and H 11--3505.8 kJ }--393.5 kJ CsH12(l) + 8O2(g) 5CO2(g) + 6H20(1) C(s) + O2(g) CO2(g) 2H2(g) + O2(g) 2H2O(1) Calculate ,on for the following reaction: AH- 483.5 kJ 5C(s) + 6H2(g) C5H12(1) 8. Given: AHf for [Ho) -286 kJ/mol; NO(g)-90 kJ/mol: NO-(g)-34 kJ/mol; HNO;--207 kJ/mol Calculate Han for the reaction: 3NO2(g) + H2O(l) 2HNO3(aq) + NO(g)

Explanation / Answer

Ans1. q = m c dT = 1.50 * 4.18 * (100- 25) = 470.25 J

Ans2. C3H8(g) + O2(g) = CO2(g) + H2O(g)

44g of C3H8 produce 2217 KJ of heat

155.5g of C3H8 produce 2217 * 155.5 / 44 = 7835 KJ of heat is produced

Ans 3 dE = q + w = 3452 + 11 = 3463 KJ

(b) Combustion is an exothermic process

Ans 4 890 KJ of heat is released by 16 g of methane

267 KJ of heat is released by 16 * 267 / 890 = 4.8 g of methane