Chemical and physical changes 12. For the following question, assume a chemical change that is endothermic taking place at constant p =1 bar. %3D a. What is meant by a chemical change? b. What is the sign of the enthalpy change in this endothermic process? c. Assuming this chemical change can be described by standard enthalpy of formation values, what conditions does the change take place under (what state? What temperature can be assumed if not stated)? d. Explain why an endothermic chemical change both requires and releases energy. Your explanation should include what is occurring on the molecular level.

Chemical and physical changes 12. For the following question, assume a chemical change that is endothermic taking place at constant p =1 bar. %3D a. What is meant by a chemical change? b. What is the sign of the enthalpy change in this endothermic process? c. Assuming this chemical change can be described by standard enthalpy of formation values, what conditions does the change take place under (what state? What temperature can be assumed if not stated)? d. Explain why an endothermic chemical change both requires and releases energy. Your explanation should include what is occurring on the molecular level.

Chemistry

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...

See similar textbooks

Similar questions

7. An old "trick" for cooling down a hot beverage quickly is to immerse a cold spoon into the liquid. A silver spoon weighing 3.20 oz and at a temperature of 20°C is placed in a cup of hot coffee (8.00 oz) at 70°C. What will be the resulting liquid temperature? Assume that specific heat of coffee is 4.18 J g-1 °C-1 and that of silver is 0.234 J g-¹ °C-1. Comment on the effectiveness of this method of cooling a hot drink. 1 g = 0.0352 oz
Write the thermochemical equation for the following reactions that occur at constant pressure: a. Decomposition of mercuric oxide, HgO, to mercury and oxygen gas, requires 87.1 kJ of heat b. Combustion of hexane, CH, to carbon dioxide gas and water, re- leases 3923.9 kJ of heat c. Reaction between solid phosphorous, P, and oxygen gas, produces P.O, and 1640.1 kJ of heat d. One mole ammonium nitrate dissolves in water to produce aqueous ammonium ions and nitrate ions, accompanied by the absorption of 28.1 kJ of heat e. Formation of carbon dioxide gas from carbon (graphite) and oxygen, yields 393.5 kJ of heat 12? 4
1.What happens to the heat capacity (CP) of a metal sample if its mass is doubled? Explain your answer[hint: examine the units and consider using the terms “intensive” or “extensive” in your answer]. 2.What happens to the specific heat (cs) of a metal sample if its mass is doubled? Explain your answer [hint:examine the units and consider using the terms “intensive” or “extensive” in your answer].
A solution is made by mixing 287.0 mL287.0 mL of ethanol initially at 13.1 ∘C13.1⁢ ∘C with 287.0 mL287.0 mL of water initially at 22.0 ∘C22.0⁢ ∘C. What is the final temperature of the solution assuming that no heat is lost? The density of ethanol is 0.789 g/mL0.789 g/mL and the density of water is 1.00 g/mL1.00 g/mL. The specific heat of ethanol is 2.46 J/g·°C2.46 J/g·°C and the specific heat of water is 4.184 J/g·°C4.184 J/g·°C.
A 0.1375g sample of solid Mg is burned in a constant volume bomb calorimeter that has a heat capacity of 3024 J/0C. The temperature increases by 1.1260C. Calculate the heat given off by the burning Mg in kJ/g Mg and kJ/mole Mg
Calculate the calorimeter constant for her calorimeter by following the steps below. 1. Calculate the mass of the warm water. 2. Calculate the change in temperature of the warm water. 3. Calculate the heat lost by the warm water. 4. Calculate the mass of the cold ocean water. 5. Calculate the change in temperature of the cold water. 6. Calculate the heat gained by the cold water. 7. Calculate the heat lost to the surroundings. 8. Calculate the calorimeter constant.
What is the enthalpy change, Delta Hrxn, for the following reaction? 2 RbI (s) + Cl2 (g) --> 2 RbCl (s) + I2 (s) a. 1.33 x 103 kJ b. 656 kJ c. – 215 kJ d. 107 kJ e. 763 kJ f. none of these g. – 1.33 x 103 kJ h. 871 kJ
According to the following thermochemical equation, how much heat is produced when 3.85 g of CHL is burned in excess O2. . Fall 2 CH (8) + 2 O2 (g) CO2e+2 H,O AH +2 H2O (g) AH = 802 kJ 192KJ b. 385 kJ C. 802 kJ d. 96KJ e. Not listed 5. 0OMHCL what volume of the 12 M HCl do you need? You have a solution of 12 M HCI. f you want to dilute this to a 100. mL solu
A student followed the procedure in this experiment, using 50.00 mL of 2.00 molar HCl and 51.00 mL of 2.00 molar NaOH both solutions having an initial temperature of 22.7 oC. After mixing, a maximum temperature of 32.2 oC is measured. The final mass of the mixture was found to be 104.84 grams. For this problem, assume the specific heat of the solution is 4.18 J/g oC. Report all answers with the proper number of significant figures. What is the heat transferred by this reaction, in Joules?
Which statement describes the effect of adding more energy to a system, assuming a phase change does not occur? O The particles within the system will have less motion, and the temperature will increase. O The particles within the system will have less motion, and the temperature will decrease. O The particles within the system will have greater motion, and the temperature will decrease. O The particles within the system will have greater motion, and the temperature will increase.
Acetylene (CH2) is commonly used as a fuel for welding. a) Write a balanced chemical equation that describes the combustion of acetylene. b) Calculate AHrn for the combustion of 1 mole of acetylene. c) A steel MC cylinder can contain 310 grams of acetylene. Calculate the heat released by the combustion of the acetylene in 1 steel MC cylinder. d) How much water can you warm from 20 °C to 90 °C using 310 grams of acetylene. e) How much ice can you melt at 0 °C using 310 grams of acetylene.
59.8 J was required to raise the temperature of 25.0 g of ethylene glycol by 1.00 K. Calculate the specific heat capacity of ethylene glycol. O a. 2.39 J/g.K O b. None of the above O c. 2.03 J/g.K O d. 1.39 J/g.K Next page Documents Jump to...