Which statement best describes the First Law of Thermodynamics? Change in internal energy of a system is path-independent Energy is neither created nor destroyed, rather it is conserved Heat flows from an object at a higher temperature to an object at a lower temperature Mass is neither created nor destroyed, rather it is conserved

Which statement best describes the First Law of Thermodynamics? Change in internal energy of a system is path-independent Energy is neither created nor destroyed, rather it is conserved Heat flows from an object at a higher temperature to an object at a lower temperature Mass is neither created nor destroyed, rather it is conserved

Chemistry for Engineering Students

4th Edition

ISBN:9781337398909

Author:Lawrence S. Brown, Tom Holme

Publisher:Lawrence S. Brown, Tom Holme

Chapter10: Entropy And The Second Law Of Thermodynamics

Section: Chapter Questions

Problem 10.27PAE: One statement of the second law of thermodynamics is that heat cannot be turned completely into...

See similar textbooks

Similar questions

9.20 State the first law of thermodynamics briefly in your own words.
9.42 Why is enthalpy generally more useful than internal energy in the thermodynamics of real world systems?
Explain in your own words what is meant by the term entropy. Explain how both matter spread and energy spread are related to the concept of entropy.
Coal is used as a fuel in some electric-generating plants. Coal is a complex material, but for simplicity we may consider it to be a form of carbon. The energy that can be derived from a fuel is sometimes compared with the enthalpy of the combustion reaction: C(s)+O2(g)CO2(g) Calculate the standard enthalpy change for this reaction at 25C. Actually, only a fraction of the heat from this reaction is available to produce electric energy. In electric generating plants, this reaction is used to generate heat for a steam engine, which turns the generator. Basically the steam engine is a type of heat engine in which steam enters the engine at high temperature (Th), work is done, and the steam then exits at a lower temperature (Tl). The maximum fraction, f, of heat available to produce useful energy depends on the difference between these temperatures (expressed in kelvins), f = (Th Tl)/Th. What is the maximum heat energy available for useful work from the combustion of 1.00 mol of C(s) to CO2(g)? (Assume the value of H calculated at 25C for the heat obtained in the generator.) It is possible to consider more efficient ways to obtain useful energy from a fuel. For example, methane can be burned in a fuel cell to generate electricity directly. The maximum useful energy obtained in these cases is the maximum work, which equals the free-energy change. Calculate the standard free-energy change for the combustion of 1.00 mol of C(s) to CO2(g). Compare this value with the maximum obtained with the heat engine described here.
The reaction SO3(g)+H2O(l)H2SO4(aq) is the last step in the commercial production of sulfuric acid. The enthalpy change for this reaction is 227 kJ. In designing a sulfuric acid plant, is it necessary to provide for heating or cooling of the reaction mixture? Explain.
9.47 If 14.8 kJ of heat is given off when 1.6 g of HCl condenses from vapor to liquid, what is Hcond for this substance?
One statement of the second law of thermodynamics is that heat cannot be turned completely into work. Another is that the entropy of the universe always increases. How are these two statements related?
9.54 The phase change between graphite and diamond is difficult to observe directly. Both substances can be hurned, however. From these equations, calculate H for the conversion of diamond into graphite. C(s,graphite)+O2(g)CO2(g) H= -393.51 kJ C(s,diamond)+O2(g)CO2(g) H= -395.94 kJ
The enthalpy of combustion of solid carbon to form carbon dioxide is 393.7 KJ/mol carbon, and the enthalpy of combustion of carbon monoxide to form carbon dioxide is 283.3 KJ/mol CO. Use these data to calculate H for the reaction 2C(s)+O2(g)2CO(g)
10.101 Fluorine reacts with liquid water to form gaseous hydrogen fluoride and oxygen. (a) Write a balanced chemical equation for this reaction. (b) Use tabulated data to determine the free energy change for the reaction and comment on its spontaneity. (c) Use tabulated data to calculate the enthalpy change of the reaction. (d) Determine how much heat flows and in what direction when 34.5 g of fluorine gas is bubbled through excess water.
When 1.000 g of ethylene glycol, C2H6O2, is burned at 25C and 1.00 atmosphere pressure, H2O(l) and CO2(g) are formed with the evolution of 19.18 kJ of heat. a Calculate the molar enthalpy of formation of ethylene glycol. (It will be necessary to use data from Appendix C.) b Gf of ethylene glycol is 322.5 kJ/mol. What is G for the combustion of 1 mol ethylene glycol? c What is S for the combustion of 1 mol ethylene glycol?
The overall reaction that occurs when sugar is metabolized is C12H22O11(s)+12O2(g)12CO2(g)+11H2O(l) For this reaction, H° is -5650 kJ and G° is -5790 kJ at 25°C. (a) If 25% of the free energy change is actually converted to useful work, how many kilojoules of work are obtained when one gram of sugar is metabolized at body temperature, 37°C? (b) How many grams of sugar would a 120-lb woman have to eat to get the energy to climb the Jungfrau in the Alps, which is 4158 m high? ( w=9.79103mh, where w= work in kilojoules, m is body mass in kilograms, and h is height in meters.)