HomeClass Notes1,200,000US530,000

CHEM-C 117 Lecture Notes - Lecture 10: State Function, Ionic Compound, Joule

25 views8 pages

20 Jul 2016

School

Department

Course

Professor

Raghavachari Krishnan

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

C117 chapter 17 notes- thermodynamics: entropy, free energy, equilibrium. 4-13-16: endothermic reactions are exceptions; heat absorbed and temperature drops, but they still proceed (cid:1837)=(cid:885). (cid:885) (cid:883)(cid:882)(cid:2876)(cid:2869) (cid:1837)=(cid:886). (cid:887) (cid:883)(cid:882) (cid:2871)(cid:2869) Predicting the direction of chemical reactions: recall energy/enthalpy is big factor: (cid:884) (cid:1834)(cid:2870)(cid:4666)(cid:3034)(cid:4667)+(cid:1841)(cid:2870)(cid:4666)(cid:3034)(cid:4667) (cid:884) (cid:1834)(cid:2870)(cid:1841)(cid:4666)(cid:3039)(cid:4667) (cid:1840)(cid:2870)(cid:4666)(cid:3034)(cid:4667)+(cid:1841)(cid:2870)(cid:4666)(cid:3034)(cid:4667) (cid:884) (cid:1840)(cid:1841)(cid:4666)(cid:3034)(cid:4667) Whether or not dissolution is endothermic depends on relative size of these 2 contributions. Suppose i randomly select the positions of the 9 ions in my 10 x 10 grid. Imagine the atoms as balls and i shake everything. In crystal, first ion can be in any of 8 spots along second-to-bottom row, second ion anywhere around that, etc. - total of 64 ways to arrange crystal lattice. How many times will i need to shake, on average, before i get a crystallized state? (cid:2874). (cid:2877) (cid:2869)(cid:2868)(cid:3117)(cid:3123)=(cid:891). (cid:885) (cid:883)(cid:882) (cid:2869)(cid:2875) System spends 1 second, on average, crystallized every 342 million years.

Related textbook solutions

Chemistry: Structure and Properties

ISBN: 9780134293936

Basic Chemistry

ISBN: 9780134138046

Principles of Chemistry Molecular Approach

ISBN: 9780134112831

Chemistry: Structure and Properties

ISBN: 9780134293936

Principles of Chemistry Molecular Approach

3rd Edition, 2014

ISBN: 9780321971944

Chemistry: A Molecular Approach

ISBN: 9780321809247

Chemistry: A Molecular Approach

ISBN: 9780134874371

Principles of Chemistry: A Molecular Approach

ISBN: 9780134895741

Chemistry: The Central Science

14th Edition, 2017

ISBN: 9780134414232

Related Documents

CHEM 1A03 Chapter Notes -Sodium Chloride, Sodium Bromide, Alkali Metal

CHM135H1 Chapter Notes - Chapter 1-4: Perchlorate, Ionic Compound, Nitrous Acid

CHM 2045 Lecture Notes - Lecture 1: Lattice Energy, Exothermic Process, Sodium Chloride

aquamarineshark960

Related Questions

fuchsiaprairie-dog12

D. 1. Silver chloride is not soluble in water. What are the relative strengths of the intermolecular forces between Ag and Ciions and water molecules as compared to the intermolecular forces between water molecules and the forces that hold the silver chloride as a solid? a. The ionic attractions are stronger than the polar covalent bonds between the H' and O ions of the b. The ionic attractions are weaker than the intermolecular forces between the Ag' and Cr ions and water c. The ionic attractions are stronger than the intermolecular forces between the Ag' and Cr ions and water d. The ionic attractions are the same as the intermolecular forces between the Ag and CI ions and water water molecules. molecules. molecules molecules 2. The value of AHsotn for a water soluble compound is +34 kJ moÄ¾1. Which value for this compound would be numerically larger, its lattice energy or its hydration energy? Select the single best answer. step. b. The lattice energy, because it is the endothermic step c. The hydration energy, because it is the exothermic step. d. The lattice energy, because it is the exothermic step. 3, which of the following are reasons why the value of ì¨,on for a gas such as CO2, dissolving in water, is negative? a. When a gas dissolves in a liquid, there is no endothermic step as with the lattice energy of a solid. b. When a gas dissolves in a liquid, there is only an exothermic step as with the lattice energy of a solid. c. The only enthalpy change is the one associated with hydration, and this is always positive. d. The only enthalpy change is the one associated with hydration, and this is always negative. e. When a gas dissolves in a liquid the lattice energy is always higher than the hydration energy, making the net enthalpy always negative. 4. Why is ammonia so much more soluble in water than is nitrogen? a. The triple bond in nitrogen prevents it from dissolving in water. b. Nitrogen has only London forces, while both water and ammonia form hydrogen bonds. c. The molar mass of nitrogen is much larger than the molar mass of ammonia, which reduces its solubility. d. Diatomic molecules are never soluble in water s which agueous solution, if either, is likely to have the highÏr boiling point 50 m Nal or en-Na e au

The chemical equation for the dissolution of lithium chloride LiCl is: LiCl_(s)+H₂O=Li⁺_(aq)+Cl^-_(aq)

ΔH = -37.4 kJ/mol.

Select the ΔH values associated with the dissolution of lithium chloride that are exothermic

a. ΔH1: energy associated with the separation of water molecules

b. ΔH2: energy associated with the separation of LiCl ions

c. ΔH3: energy associated with the formation of water-ion interaction

d. ΔH: The enthalpy of reaction

Predict what must happen when a beaker containing a solution of lithium chloride is heated.

a. The ΔH will decrease

b. The reaction will become endothermic

c. The ΔH3 value will increase

d. Energy will be transferred into the system

cyanhippopotamus115