Prelaboratory Questions Name Laboratory Section 8. 1. The temperature of a 15.0 g sample of a metal (specific heat 0.040 J/g-°C) is raised by 18.2°C. How much heat (in J) has been absorbed by the metal? 2. A calorimeter and its contents have a heat capacity of 70 J/°C. A reaction occurs in this calorimeter at atmospheric pressure. The temperature of the system rises 10.5°C when one mole of product is formed. Calculate the heat change for this reaction. 3. If 100 g of a solution (specific heat of 0.32 J/g-°C) undergoes a reaction in which 74.84 J of heat is released, what is the temperature change (AT) of this solution? Does the tem-

Prelaboratory Questions Name Laboratory Section 8. 1. The temperature of a 15.0 g sample of a metal (specific heat 0.040 J/g-°C) is raised by 18.2°C. How much heat (in J) has been absorbed by the metal? 2. A calorimeter and its contents have a heat capacity of 70 J/°C. A reaction occurs in this calorimeter at atmospheric pressure. The temperature of the system rises 10.5°C when one mole of product is formed. Calculate the heat change for this reaction. 3. If 100 g of a solution (specific heat of 0.32 J/g-°C) undergoes a reaction in which 74.84 J of heat is released, what is the temperature change (AT) of this solution? Does the tem-

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

Chapter6: Thermochemistry

Section: Chapter Questions

Problem 49E: The overall reaction in a commercial heat pack can be represented as 4Fe(s)+3O2(g)2Fe2O3(s)H=1652KJ...

See similar textbooks

Similar questions

You wish to heat water to make coffee. How much heat (in joules) must be used to raise the temperature of 0.180 kg of tap water (enough for one cup of coffee) from 30C to 96C (near the ideal brewing temperature)? Assume the specific heat is that of pure water, 4.18 J/(gC).
The overall reaction in a commercial heat pack can be represented as 4Fe(s)+3O2(g)2Fe2O3(s)H=1652KJ a. How much heat is released when 4.00 moles of iron are reacted with excess O2? b. How much heat is released when 1.00 mole of Fe2O3 is produced? c. How much heat is released when 1.00 g iron is reacted with excess O2? d. How much heat is released when 10.0 g Fe and 2.00 g O2 are reacted?
Consider the following specific heats of metals. Metal Specific Heat copper 0.385 J/(gC) magnesium 1.02 J/(gC) Mercury 0.138 J/(gC) Silver 0.237 J/(gC) Four 25-g samples, one of each metal, and four insulated containers with identical water volumes, all start out at room temperature. Now suppose you add exactly the same quantity of heat to each metal sample. Then you place the hot metal samples in different containers of water (that all have the same volume of water). Which of the answers below is true? a The water with the copper will be the hottest. b The water with the magnesium will be the hottest. c The water with the mercury will be the hottest. d The water with the silver will be the hottest. e The temperature of the water will be the same in all the cups.
A 500.0-g sample of an element at 195C is dropped into an ice--water mixture; 109.5 g ice melts and an ice--water mixture remains. Calculate the specific heat of the element. See Exercise 131 for pertinent information.
A 110.-g sample of copper (specific heat capacity = 0.20 J/C g) is heated to 82.4C and then placed in a container of water at 22.3C. The final temperature of the water and copper is 24.9C. What is the mass of the water in the container, assuming that all the heat lost by the copper is gained by the water?
In a calorimetric experiment, 6.48 g of lithium hydroxide, LiOH, was dissolved in water. The temperature of the calorimeter rose from 25.00C to 36.66C. What is H for the solution process? LiOH(s)Li(aq)+OH(aq) The heat capacity of the calorimeter and its contents is 547 J/C.
9.97 Suppose that the working fluid inside an industrial refrigerator absorbs 680 J of energy for every gram of material that vaporizes in the evaporator. The refrigerator unit uses this energy flow as part of a cyclic system to keep foods cold. A new pallet of fruit with a mass of 500 kg is placed in the refrigerator. Assume that the specific heat of the fruit is the same as that of pure water because the fruit is mostly water. Describe how you would determine the mass of the working fluid that would have to be evaporated to lower the temperature of the fruit by 15C. List any information you would have to measure or look up.
The Group 2A carbonates decompose when heated. For example, MgCO3(s)MgO(s)+CO2(g) Use enthalpies of formation (see Appendix C) and calculate the heat required to decompose 10.0 g of magnesium carbonate.
Limestone, CaCO3, when subjected to a temperature of 900C in a kiln, decomposes to calcium oxide and carbon dioxide. How much heat is evolved or absorbed when one gram of limestone decomposes? (Use Table 8.3.)
Alloys When a 58.8-g piece of hot alloy is placed in125 g of cold water in a calorimeter, the temperature ofthe alloy decreases by 106.1°C, while the temperature ofthe water increases by 10.5°C. What is the specific heat ofthe alloy?
When calcium carbonate, CaCO3 (the major constituent of limestone and seashells), is heated, it decomposes to calcium oxide (quicklime). CaCO3(s)CaO(s)+CO2(g);H=177.9kJ How much heat is required to decompose 21.3 g of calcium carbonate?
How much heat is absorbed by a 44.7-g piece of leadwhen its temperature increases by 65.4°C?