13. Liquids, Solids & Intermolecular Forces

Heating and Cooling Curves

The Heating and Cooling Curves.

Heating and Cooling Curves Concept 2

Use the normal boiling points propane (C3H8) -42.1 °C butane (C4H10) -0.5 °C pentane (C5H12) 36.1 °C hexane (C6H14) 68.7 °C heptane (C7H16) 98.4 °C to estimate the normal boiling point of octane (C8H18). Explain the trend in the boiling points.

If 53.2kJ of heat are added to a 15.5g ice cube at - 5.00 oC, what will be the resulting state and temperature of the substance?

If 42.0 kJ of heat is added to a 32.0-g sample of liquid meth-ane under 1 atm of pressure at a temperature of -170°C, what are the final state and temperature of the methane once the system equilibrates? Assume no heat is lost to the surroundings. The normal boiling point of methane is -161.5 °C. The specific heats of liquid and gaseous methane are 3.48 and 2.22 J/g-K, respectively. [Section 11.3] <img src="https://lightcat-files.s3.amazonaws.com/problem_images/086810f695de480b-1674835181839.jpg" alt="" />

Heating Curves Temperature Energy Graphs | GCSE Physics

How much energy in kilojoules is needed to heat 5.00 g of ice from -11.0 °C to °30.0 °C? The heat of fusion of water is 
6.01 kJ>mol, and the m# olar heat capacity is 36.01 kJ>mol for ice and 75.4 J/K mol2 for liquid water

Phase Changes, Heats of Fusion and Vaporization, and Phase Diagrams

Name the phase transition in each of the following situa- tions and indicate whether it is exothermic or endother- mic: (d) Molten lava from a volcano turns into solid rock.

Name the phase transition in each of the following situa- tions and indicate whether it is exothermic or endother- mic: (c) Rubbing alcohol in an open container slowly disappears.

Heating Curves Tutorial: How to Calculate enthalpy changes in Heating & Cooling | Crash Chemistry

An 8.5-g ice cube is placed into 255 g of water. Calculate the 
temperature change in the water upon the complete melting of 
the ice. Assume that all of the energy required to melt the ice 
comes from the water.

Suppose that 0.95 g of water condenses on a 75.0-g block of iron
that is initially at 22 °C. If the heat released during condensation
goes only to warming the iron block, what is the final temperature
(in °C) of the iron block? (Assume a constant enthalpy
of vaporization for water of 44.0 kJ/mol.)

Suppose that 1.15 g of rubbing alcohol (C3H8O) evaporates from
a 65.0-g aluminum block. If the aluminum block is initially at
25 °C, what is the final temperature of the block after the evaporation
of the alcohol? Assume that the heat required for the
vaporization of the alcohol comes only from the aluminum
block and that the alcohol vaporizes at 25 °C.

Consider a compound that has a melting point at 65 °C and a boiling point at 175 °C. Which of the following images represents a heating curve for the compound from 40 °C to 200 °C? (LO 11.5)

Mercury has mp = -38.8 °C and bp = 356.6 °C. What,if any, phase changes take place under the following condi-tions at 1.0 atm pressure? (a) The temperature of a sample is raised from -30 °C to 365 °C.

A sample of steam with a mass of 0.552 g and at a temperature of 
100 °C condenses into an insulated container holding 4.25 g of 
water at 5.0 °C. Assuming that no heat is lost to the surroundings, 
what is the final temperature of the mixture?

Heating and Cooling Curves Example 2

For many years drinking water has been cooled in hot cli- mates by evaporating it from the surfaces of canvas bags or porous clay pots. How many grams of water can be cooled from 35 to 20 °C by the evaporation of 60 g of water? (The heat of vaporization of water in this temperature range is 2.4 kJ/g. The specific heat of water is 4.18 J/g-K).

How much energy is released when 65.8 g of water freezes?

Has the Earth’s surface experienced warming as a result of 
increasing levels of greenhouse gases? If so, by how much?

How much energy in kilojoules is released when 25.0 g of ethanol vapor at 93.0 °C is cooled to -11.0 °C? Ethanol has mp = -114.1 °C, bp = 78.3 °C, ΔHvap = 38.56 kJ>mol, and ΔHfusio#n = 4.93 kJ>mol. The molar heat#capacity is 112.3 J>1K mol2 for the liquid and 65.6 J>1K vapor.

Using information in Appendices B and C, calculate the minimum grams of propane, C3H8(g), that must be combusted to provide the energy necessary to convert 5.50 kg of ice at -20 °C to liquid water at 75 °C

Ethyl chloride (C2H5Cl) boils at 12 °C. When liquid C2H5Cl under pressure is sprayed on a room-temperature (25 °C) surface in air, the surface is cooled considerably. (b) Assume that the heat lost by the surface is gained by ethyl chloride. What enthalpies must you consider if you were to calculate the final temperature of the surface?

How much ice (in grams) would have to melt to lower the temperature
of 352 mL of water from 25 °C to 5 °C? (Assume the density of water is 1.0 g/mL.)

 Use the heat of vaporization to determine the number of moles of acetone, then molar mass to determine grams and finally the density to convert to volume. 

 The conversion from mass to volume involves dividing by the density. 

 This numerical value is the mass of acetone vaporized in grams. 

 Correct, a fairly large volume since acetone is very volatile. 

The heat of vaporization (&#916;Hvap) relates heat absorbed and moles of a substance vaporized

Calculate the volume (mL) of acetone, C3 H6 O, (density = 0.786 g/mL) that can be vaporized at its normal boiling point with 345 kJ of heat. &#916;Hvap for acetone is 29.1 kJ/mol.

The compound cholesteryl benzoate is a rod-like molecule that undergoes a phase change from the solid to the liq- uid crystal phase at 145.5 °C. When cholesteryl benzoate is mixed with cholesteryl oleyl carbonate, a molecule with a curved shape, the temperature of the solid to liquid crys- tal transition changes. Predict if the transition temperature increases or decreases and explain your reasoning.

Heating and Cooling Curves Concept 1

How much energy (kJ) is required to convert a 76.4 g acetone (MM = 58.08 g/mol) as a liquid at -30°C to a solid at -115.0°C?

 Apply the Clausius-Clapeyron equation with the temperatures given in kelvins be sure you have the correct correlation between T and P. 

 Correct, the vapor pressure will be low since the temperature is well below the boiling point. 

 Using the Clausius-Clapeyron equation, the units on energy in the calculation with must in J. 

 A sign error was made in obtaining this value. 

 This value is the natural log of the vapor pressure. 

The Clausius-Clapeyron equation relates vapor pressure, temperature, and &#916;Hvap.

Determine the vapor pressure (atm) of rubbing alcohol (isopropanol) at 20.0&#x2103;. The normal boiling point of isopropanol is 82.3&#x2103; and the heat of vaporization (&#916;Hvap) is 39.9 kJ/mol.

Heating and Cooling Curves Example 1

Calculate the amount of heat required to completely sublime
50.0 g of solid dry ice (CO2) at its sublimation temperature. The
heat of sublimation for carbon dioxide is 32.3 kJ/mol.

Heating and Cooling Curves Concept 3

Why is the heat of sublimation, ΔHsubl, equal to the sum of ΔHvap and ΔHfusion at the same temperature?

Heating Curve and Cooling Curve of Water - Enthalpy of Fusion & Vaporization

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VT Physics

1. Intro to General Chemistry

2. Atoms & Elements

3. Chemical Reactions

4. BONUS: Lab Techniques and Procedures

5. BONUS: Mathematical Operations and Functions

6. Chemical Quantities & Aqueous Reactions

7. Gases

8. Thermochemistry

9. Quantum Mechanics

10. Periodic Properties of the Elements

11. Bonding & Molecular Structure

12. Molecular Shapes & Valence Bond Theory

14. Solutions

15. Chemical Kinetics

16. Chemical Equilibrium

17. Acid and Base Equilibrium

18. Aqueous Equilibrium

19. Chemical Thermodynamics

20. Electrochemistry

21. Nuclear Chemistry

22. Organic Chemistry

23. Chemistry of the Nonmetals

24. Transition Metals and Coordination Compounds

[BOOK CHEM] Clutch Version

Body Centered Cubic Unit Cell

Body Centered Cubic Unit Cell contains 2 atoms total.

Phase Diagrams

Phase&nbsp;Diagrams show&nbsp;what&nbsp;effect&nbsp;temperature and pressure have&nbsp;on a pure substance in a closed system without any air.

Intermolecular Forces and Physical Properties

Intermolecular forces influence physical properties. &nbsp;We will look at direct and indirect relationships.

Face Centered Cubic Unit Cell

Face Centered Cubic Unit Cell contains 4 atoms in total.

Heating and Cooling Curves represent amount of heat (q) absorbed or released by a substance during phase changes.

Clausius-Clapeyron Equation

The Clausius-Clapeyron Equation establishes a quantitative relationship between vapor pressure and temperature.&nbsp;

Molecular Polarity

Polarity of chemical bonds happen in molecules when there is an unequal sharing of electrons.&nbsp;

Intermolecular Forces

Intramolecular Forces are the bonding forces within a molecule. Intermolecular Forces are the attractive forces between 2 molecules.

Simple Cubic Unit Cell

Simple Cubic Unit Cell is the least complex&nbsp;cubic unit cell and contains only 1 atom.

Atomic, Ionic, and Molecular Solids

<div dir="auto"><div contenteditable="true"dir="auto"spellcheck="true">Crystalline solids represent structures with well-organized patterns and shapes. Amorphous solids represent structures that lack an organized pattern or shape.&nbsp;</div></div>

Crystalline Solids

Crystalline Solids are composed of unit cells, crystal lattice and lattice point.