3. Sodium chloride, calcium chloride, and urea have all been used to melt ice from sidewalks. If each of these substances costs the same per kilogram, which would be the most effective ice melter? (There are environmental considerations, too, but we will neglect those here!) Show your work and support your choice with evidence. a. N₂H4CO (urea) b. NaCl c. CaCl₂

20.) You want to raise the temperature of ice at 0 degrees Celsius to steam at 110 degrees O Celsius. The specific heat of water is 4.184 J/Cg. The specific heat of steam is 2.01 J/Cg, and the specific heat of ice is 2.03 J/Cg. Ice has a heat of fusion at 334 J/g and water has a heat of vaporization of 2260 J/g. Find the Q for this raise in temperature.

1. Suppose the sun were used as a heat source to warm some water in a solar-heated house or swimming pool. How much (solar) energy (in both kcal and kJ) is stored in a filled 750-liter water tank when the temperature of the water is raised from 25EC to 65EC? 2. How many kcal are needed to convert 20 g of ice at 0EC to steam at 100EC? 3. What would be the final temperature of the water resulting from the addition of 20 g of steam at 100EC to 80 g of ice at 0EC?

B. Explain why the maximum vapor pressure and standard enthalpy of vaporization are different for the morning low temperature and the afternoon high temperature in the month of August in Philadelphia. a. Having trouble? Review questions from Chapter 10: 35, 37, and 47. Temperature Vapor Pressure Enthalpy of Vaporization Morning Low 70 °F 18.7 mmHg 44.16 kJ/mol Afternoon High 87 °F 33.7 mmHg 43.75 kJ/mol

How much energy is needed to vaporize 1.56 kg of water at 100 °C? Record the energy in kJ. For water, AHvap = 42.1 kJ/mol (at 100 °C) %3D O 2.11 kJ 5.69 x 103 k O 2.14 x 108k) O 5692 kJ A Moving to another question will save this response. 432 MAY 山 / A 16 ttv MacBook Pro Q Search Web Safety 3 4 5 6 7 8 9

The melting point of calcium is 851 oC, its solid-state specific heat (Csolid) is 0.632 J/goC, and its heat of fusion (ΔHfus) is 233 J/g. How much energy, in joules, is required to melt 52.0 g of calcium at each of the following initial temperatures? a. its melting pointb. 35.0 oCc. 685 oC below its melting point