Concept explainers
When a solution containing 8.00 g of NaOH in 50.0 g of water at 25.0 °C is added to a solution of 8.00 g of HCI in 250.0 g of water at 25.0 °C in a calorimeter, the temperature of the solution increases to 33.5 °C. Assuming that the specific heat of the solution is 4.18 J/(g .°C) and that the calorimeter itself absorbs a negligible amount of heat, calculate
When the experiment is repeated using a solution of 10.00 g of HCI in 248.0 g of water, the same temperature increase is observed. Explain.
Want to see the full answer?
Check out a sample textbook solutionChapter 9 Solutions
CHEMISTRY-TEXT
- In a coffee-cup calorimeter, 100.0 mL of 1.0 M NaOH and 100.0 mL of 1.0 M HCI are mixed. Both solutions were originally at 24.6C. After the reaction, the final temperature is 31.3C. Assuming that all the solutions have a density of 1.0 g/cm3 and a specific heat capacity of 4.18 J/Cg, calculate the enthalpy change for the neutralization of HCl by NaOH. Assume that no heat is lost to the surroundings or to the calorimeter.arrow_forwardA sample of benzene, C6H6, weighing 3.51 g was burned in an excess of oxygen in a bomb calorimeter. The temperature of the calorimeter rose from 25.00C to 37.18C. If the heat capacity of the calorimeter and contents was 12.05 kJ/C, what is the value of q for burning 1.00 mol of benzene at constant volume and 25.00C? The reaction is C6H6(l)+152O2(g)6CO2(g)+3H2O(l) Is q equal to U or H?arrow_forwardWhen 1.0 g of fructose, C6H12O6(s), a sugar commonly found in fruits, is burned in oxygen in a bomb calorimeter, the temperature of the calorimeter increases by 1.58 C. If the heat capacity of the calorimeter and its contents is 9.90 kJ/C, what is q for this combustion?arrow_forward
- A sample of ethanol, C2H5OH, weighing 2.84 g was burned in an excess of oxygen in a bomb calorimeter. The temperature of the calorimeter rose from 25.00C to 33.73C. If the heat capacity of the calorimeter and contents was 9.63 kJ/C, what is the value of q for burning 1.00 mol of ethanol at constant volume and 25.00C? The reaction is C2H5OH(l)+3O2(g)2CO2(g)+3H2O(l) Is q equal to U or H?arrow_forwardConsider the reaction 2HCl(aq)+Ba(OH)2(aq)BaCl2(aq)+2H2O(l)H=118KJ Calculate the heat when 100.0 rnL of 0.500 M HCl is mixed with 300.0 mL of 0.100 M Ba(OH)2 Assuming that the temperature of both solutions was initially 25.0C and that the final mixture has a mass of 400.0 g and a specific heat capacity of 4.18 J/C g, calculate the final temperature of the mixture.arrow_forwardA student performing a calorimetry experiment combined 100.0 ml. of 0.50 M HCI and 100.0 ml. of 0.50 M NaOH in a StyrofoamTM cup calorimeter. Both solutions were initially at 20.0 C, but when the two were mixed, the temperature rose to 23.2 C (a) Suppose the experiment is repeated in the same calorimeter but this time using 200 mL of 0.50 M HCl and 200.0 ml of 0.50 M NaOH. WIII the AT observed be greater than, less than, or equal to that in the first experiment, and why? (b) Suppose that the experiment is repeated once again in the same calorimeter, this time using 100 mL of 1.00 M HCI and 100.0 ml. of 1.00 M NaOH. Will the T observed be greater than, less than, or equal to that in the first experiment, and why?arrow_forward
- 9.50 When a 13.0-g sample of NaOH(s) dissolves in 400.0 mL of water in a coffee cup calorimeter, the temperature of the water changes from 22.6°C to 30.7C Assuming that the specific heat capacity of the solution is the same as for water, calculate (a) the heat transfer from system to surroundings and (b) H for the reaction NaOH(s)Na+(aq)+OH(aq)arrow_forwardYou did an experiment in which you found that 59.8 J was required to raise the temperature of 25.0 g of ethylene glycol (a compound used as antifreeze in automobile engines) by 1.00 K. Calculate the specific heat capacity of ethylene glycol from these data.arrow_forwardA 237-g piece of molybdenum, initially at 100.0 C, is dropped into 244 g of water at 10.0 C. When the system comes to thermal equilibrium, the temperature is 15.3 C. What is the specific heat capacity of molybdenum?arrow_forward
- One of the components of jet engine fuel is n-dodecane, C12H26(), which has a standard enthalpy of combustion of 8080.1 kJ/mol. (a) Write the thermochemical equation for the combustion of n-dodecane. (b) Use the standard enthalpies of formation in Appendix G to calculate the standard enthalpy of formation of n-dodecane.arrow_forwardNitrogen gas (2.75 L) is confined in a cylinder under constant atmospheric pressure (1.01 105 pascals). The volume of gas decreases to 2.10 L when 485 J of energy is transferred as heat to the surroundings. What is the change in internal energy of the gas?arrow_forwardThe head of a strike anywhere match contains tetraphosphorus trisulfide, P4S3. In an experiment, a student burned this compound in an excess of oxygen and found that it evolved 3651 kJ of heat per mole of P4S3 at a constant pressure of 1 atm. She wrote the following thermochemical equation: P4S3(s)+8O2(g)P4O10(s)+3SO2(g);H=3651kJ Calculate the standard enthalpy of formation of P4S3, using this students result and the following standard enthalpies of formation: P4O10(s), 3009.9 kJ/mol; SO2(g), 296.8 kJ/mol. How does this value compare with the value given in Appendix C?arrow_forward
- Chemistry: An Atoms First ApproachChemistryISBN:9781305079243Author:Steven S. Zumdahl, Susan A. ZumdahlPublisher:Cengage LearningChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage LearningChemistry for Engineering StudentsChemistryISBN:9781337398909Author:Lawrence S. Brown, Tom HolmePublisher:Cengage Learning
- General 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 Engineering StudentsChemistryISBN:9781285199023Author:Lawrence S. Brown, Tom HolmePublisher:Cengage Learning