(a)
Interpretation:
Convert 625.2 cal to kilojoules.
Concept Introduction:
A conversion factor is a numerical ratio which is used to show a measurement in one unit as another unit. It is always equal to 1.
(b)
Interpretation:
Convert 82.41 kilojoules to joules.
Concept Introduction:
A conversion factor is a numerical ratio which is used to show a measurement in one unit as another unit. It is always equal to 1.
(c)
Interpretation:
Convert 52.61 kilocalories to joules.
Concept Introduction:
A conversion factor is a numerical ratio which is used to show a measurement in one unit as another unit. It is always equal to 1.
(c)
Interpretation:
Convert 124.2 kilojoules to kilocalories.
Concept Introduction:
A conversion factor is a numerical ratio which is used to show a measurement in one unit as another unit. It is always equal to 1.
Want to see the full answer?
Check out a sample textbook solutionChapter 10 Solutions
EBK INTRODUCTORY CHEMISTRY
- Insoluble AgCl(s) precipitates when solutions of AgNO3(aq) and NaCl(aq) are mixed. AgNO3(aq) + NaCl(aq) AgCl(s) + NaNO3(aq) rH = ? To measure the energy evolved in this reaction, 250. mL of 0.16 M AgNO3(aq) and 125 mL of 0.32 M NaCl(aq) are mixed in a coffee-cup calorimeter. The temperature of the mixture rises from 21.15 C to 22.90 C. Calculate the enthalpy change for the precipitation of AgCl(s), in kJ/mol. (Assume the density of the solution is 1.0 g/mL and its specific heat capacity is 4.2 J/g K.)arrow_forwardA rebreathing gas mask contains potassium superoxide, KO2, which reacts with moisture in the breath to give oxygen. 4KO2(s)+2H2O(l)4KOH(s)+3O2(g) Estimate the grams of potassium superoxide required to supply a persons oxygen needs for one hour. Assume a person requires 1.00 102 kcal of energy for this time period. Further assume that this energy can be equated to the heat of combustion of a quantity of glucose, C6H12O6, to CO2(g) and H2O(l). From the amount of glucose required to give 1.00 102 kcal of heat, calculate the amount of oxygen consumed and hence the amount of KO2 required. The ff0 for glucose(s) is 1273 kJ/mol.arrow_forwardHow much heat is required to raise the temperature of 100. grams of water from 25C near room temperature to 100.C its boiling point? The specific heat of water is approximately 4.2Jperg-K. a.3.2104J b.32J c.4.2104J d.76Jarrow_forward
- Bicycling Describe the energy conversions that occur when a bicyclist coasts down a long grade, then struggles to ascend a steep grade.arrow_forward9.89 A sample of gas is 80.0% CH4 and 20.0% C2H6 by mass. What is the heat from the combustion of 1.00 g of this mixture? Assume the products are CO2 (g) and H2O (l).arrow_forwardHypothetical elements A2 and B2 react according to the following equation, forming the compound AB. A2(aq)+B2(aq)2AB(aq);H=+271kJ/mol If solutions A2(aq) and B2(aq), starting at the same temperature, are mixed in a coffee-cup calorimeter, the reaction that occurs is a exothermic, and the temperature of the resulting solution rises. b endothermic, and the temperature of the resulting solution rises. c endothermic, and the temperature of the resulting solution falls. d exothermic, and the temperature of the resulting solution falls. e exothermic or endothermic, depending on the original and final temperatures.arrow_forward
- How much heat, in joules and in calories, must be added to a 75.0g iron block with a specific heat of 0.449 Jig C to increase its temperature from 25 C to its melting temperature of 1535 C?arrow_forwardEnthalpy a A 100.-g sample of water is placed in an insulated container and allowed to come to room temperature at 21C. To heat the water sample to 41C, how much heat must you add to it? b Consider the hypothetical reaction,2X(aq)+Y(l)X2Y(aq)being run in an insulated container that contains 100. g of solution. If the temperature of the solution changes from 21C to 31C, how much heat does the chemical reaction produce? How does this answer compare with that in part a? (You can assume that this solution is so dilute that it has the same heat capacity as pure water.) c If you wanted the temperature of 100. g of this solution to increase from 21C to 51C, how much heat would you have to add to it? (Try to answer this question without using a formula.) d If you had added 0.02 mol of X and 0.01 mol of Y to form the solution in part b, how many moles of X and Y would you need to bring about the temperature change described in part c. e Judging on the basis of your answers so far, what is the enthalpy of the reaction 2X(aq) + Y(l) X2Y(aq)?arrow_forwardClassify each process as exothermic or endothermic. (a) ice melts (b) gasoline burns (c) steam condenses (d) reactants products, H = 50 kJarrow_forward
- In the following equation for a chemical reaction, the notation s, l, or g indicates whether the substance is in the solid, liquid, or gaseous state:2H2S(g)+3O2(g)2H20(g)+2SO2(g)+energy. Identify each of the following as a product or reactant: a SO2(g); b H2S(g); c O2(g); d H20(g). When the reaction takes place, is energy released or absorbed? Is the reaction endothermic or exothermic?arrow_forwardDefine each of the following terms: a. heat b. energy c. work d. system e. surroundings f. exothermic reaction g. endothermic reaction h. enthalpy of reaction i. kinetic energy j. potential energyarrow_forwardThe equation for the fermentation of glucose to alcohol and carbon dioxide is: C6H12O6(aq) 2C2H5OH(aq) + 2CO2(g) The enthalpy change for the reaction is 67 kJ. Is this reaction exothermic or endothermic? Is energy, in the form of heat, absorbed or evolved as the reaction occurs?arrow_forward
- Introductory Chemistry: A FoundationChemistryISBN:9781337399425Author:Steven S. Zumdahl, Donald J. DeCostePublisher:Cengage LearningWorld of Chemistry, 3rd editionChemistryISBN:9781133109655Author:Steven S. Zumdahl, Susan L. Zumdahl, Donald J. DeCostePublisher:Brooks / Cole / Cengage LearningWorld of ChemistryChemistryISBN:9780618562763Author:Steven S. ZumdahlPublisher:Houghton Mifflin College Div
- Chemistry: Matter and ChangeChemistryISBN:9780078746376Author:Dinah Zike, Laurel Dingrando, Nicholas Hainen, Cheryl WistromPublisher:Glencoe/McGraw-Hill School Pub CoGeneral Chemistry - Standalone book (MindTap Cour...ChemistryISBN:9781305580343Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; DarrellPublisher:Cengage LearningChemistry for Today: General, Organic, and Bioche...ChemistryISBN:9781305960060Author:Spencer L. Seager, Michael R. Slabaugh, Maren S. HansenPublisher:Cengage Learning