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Heating and Cooling Curves

#### Q. After performing some tests on an unknown material with constant mass, a lab student produces the given heat curve. Help this student label the key points of this graph. Answer bank: temp change 3, temp change 2, vaporization, temp change 1, time, temperature, no heat added, fusion

Solved • Apr 30, 2020

Heating and Cooling Curves

#### Q. Use the changes of state interactive to answer the question. Find the melting point and boiling point of each substance. melting point of water: _____ °C boiling point of water _____ °C melting point of bromine _____ °C boiling point of bromine _____ °C melting point of benzene _____ °C boiling point of benzene _____ °C

Solved • Apr 30, 2020

Heating and Cooling Curves

#### Q. An energy source emitted 183 Kcal of heat. A chunk of ice initially at a temperature of 0C was transformed into liquid water with a temperature of 25C. Water has the following thermodynamic properties: Hfusion = 6.02 KJ/mole, Cice = 2.10 J/gC, and Cwater = 4.18 J/gC. The amount of liquid water formed is approximately?

Solved • Apr 20, 2020

Heating and Cooling Curves

#### Q. What is the energy change when 76.9g of Br2 (g) condenses into a liquid at 59.5 degrees centigrade? Given: The delta H of vaporization of Br2 is 15.4kj/mol The normal boiling point of Bromine is 59.5 degrees centigrade.

Solved • Apr 16, 2020

Heating and Cooling Curves

#### Q. If 41.2 x103 J of energy is needed to raise the temperature of 170.0 g of a liquid from 18.8oC to 65.2oC, what is the specific heat capacity of the solution? A) 4.19 J/g•oC B) 5.22 J/g•oC C) 11.2 J/g•oC D) 12.0 J/g•oC

Solved • Apr 13, 2020

Heating and Cooling Curves

#### Q. The enthalpy change for converting 10.0g of ice at -25.0 C to water at 80.0 C is ____ kJ. The specific heats of ice, water and steam are 2.09 J/gK, 4.18 J/gk and 1.84 J/gK, respectively. For H2O, Hfus=6.01 kJ/mol and Hvap= 40.67 kJ/mol. a.) 7.21 b.) 6.16 c.) 3870 d.) 12.28 e.) 9.88

Solved • Apr 11, 2020

Heating and Cooling Curves

#### Q. How many grams of ice at -21.5 ∘C can be completely converted to liquid at 16.8∘C if the available heat for this process is 4.93×103 kJ? For ice, use a specific heat of 2.01 J/(g⋅∘C) and ΔHfus=6.01 kJ/mol

Solved • Apr 3, 2020