CHE 1302 Lecture Notes - Lecture 12: Supersaturation, Molar Mass, Correlation Does Not Imply Causation

72 views9 pages

lilacseal239

10 Apr 2018

School

Department

Course

Professor

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

Document Summary

Most of chem we study takes place in solution. Has to be homogenous mixture: true solutions will never settle out, solvent. Any phase solvent is in, that"s the phase solution should be in: solute. Will mix to form solution in any proportion. However, solvent may change: may start as water but change to alcohol after you add certain amount, all solid/liquid/gas combinations are possible to form a solution, gas mixed with gas will always give you a solution. Unless they react with each other, then no solution: when two ideal gases mix spontaneously: Two factors: intermolecular forces in mixtures, enthalpy of solution ( hsolution) Enthalpy change associated with forming a solution: if both of these two factors occur, then a solution forms. 9: process when something dissolves, solute molecules move apart to distance apart that they are in solution. We have to overcome intermolecular attractions to move apart molecules. Hsolute > 0: solvent molecules move apart to accommodate solute molecules.

Related Questions

I can't seem to figure this one out. thank you!

BAEDitemViewlassignmentProblemiD-830644918offset next 121C1 12 Introduction to Solutility and Solution Formation troduction to Solubility and Solution Formation arning Goal understand the solubility of a solute in a solvent, the dissoltion p peocess, and the properties that afect the rate of dissoluÅ¡on ocess, and the properties that affed the rate of cola has a certain amount of carbon dioxide dissolved in t The cola is theretore olecular level, the dissolution process involves breaking intermolecular forces of aty action rious parameters, such as temperature, pressure, the nature of the solute, and the r example an incresse in temperature may increase the rate of dissoludon for solutions hwolving solds an example of a solution of gas in waler. The carbon daxide gas is the solute and it is diessved in water,which is nature of the solvent One can increase or decrease the solubility of solute by changing hese parameters e f the solvere At the among the solute molecules and forming new ones with the solvent moleciles The solublty af a solute in a salent depend art A The properties of a solute and its solubility in liquid solvents A solution is a homogenous mixture of solute and solvent There are diHarent types of soluions. A carbonated drink ia an example of a solution where the solute is a gas and ths saveet is a iquid Sugar crystas a in water is an example of a solution where the solute is a solid and the solvent is liquid Aceic acid is miscible in water, forming a solution commonly known as vinegar ln this case both the solure and the sohen iquids The solubility of solute in a solvent depends on various parsmeters, such as temperature pressura, tha nature of the solute, and the nature of the salvent Considaring thesa paranters iderdfy the ts correct for the solublity of a solute in a solvent Check all that apply Hints Table salt dissolves in water to form a solution Zinc sullate is soluble in water Gases are readly soluble in water t higher tamperatures Carbon dioxide gas will be more soluble in water when the partial pressure is high Propanol and heptane are miacible Dei My Awers Give Up

Experiment 10 Colligative Properties Introduction A pinch of wa make boiling water hotter. A handful will clear the snow from your steps. Every day we the physical properties of materials around us, but often don't know why we use these particular s or what chemistry is involved. Modifying the temperature of phase changes, by adding a second chemical to the pure solvent are examples of manipulating the Colligative Properties of a solution. this lab, we will study how varying the concentration and type of a salt affects the point of a solution. Colligative properties are properties of a solution containing 2 or more components. Typically, the primary is the solvent and the other called the such as color or hardness, properties depend on the number of particles of astute in the not the identity of the In many cases, the rokute will determine the number of solute particles (degree of ionization, solubility, etc,) in the solvent, but a colligative property does not depend upon the nature of the particles. Two colligative properties commonly encountered are boiling point elevation and freezing point depression (the temperature of of a is lower than of pure solvent). We will be studying boiling point elevation in this Most of the previous work that you have done with solutions has involved units of molarity, M, or moles of solute per liter of solution. Boiling point elevation calculations (as well as those for freezing point depression) or moles of solute per kilogram of solvent. boili change of temperature. When the temperature of a solution changes, the volume of the solution also changes. Since molarity depends on a change in wil the solution's molarity. Molality depends on the mass of the solvent. and thus is independent of temperature. n't Hoff Factor salt into and the of moles inorganic salts in an aque the based on the addition of the number dissociates, the total number of particles in the solution will be of cations and anions produced from the dissociation. Thus; Nacion Na Choaa (2moles of particles) Cacbrs Ca +2ch (3moles of particles) The quantity of particles produced per mole of solute is called the van'tHoff factor and is given the symbol, i, If 1 mole of sodium chloride were completely dissociated, iwould be 2. This theory works very well for dilute solutions and non-electrolytes (i 1, no dissociation at all since nonelectrolytes not ionize), For does not always apply to more concentrated solutions. Thus, when there are a large number of particles in a solution, they have a tendency to recombine as the salt and you don't get 100% dissociation. example, at a NaCl concentration of 0.1M, iwill be 1.81 (90% dissociation) rather than 2 (100%). Boiling Point Elevation solute causes the solution to boil at a higher When a solution is heated, the presence of a non-volatile point of the pure liquid and the temperature than the pure The difference between the boiling boiling point of the solution is: 169

This is for the lab practical I take on Tuesday night. If you could answer each one and show your work/ explain that'd be amazing so I can do well on the actual practical on Tuesday! Thank you!

Chemistry 211 Lab Final Study Guide Spring 2015

Useful Information:
1 ampere =coulomb/sec
Faradayâs constant = 96,500 coulombs/mole of electrons
Molar mass of Au = 197.0 g/mole, Molar mass of Cu = 63.55 g/mole
m = moles , ' â

c kg

ÎTf

= Tf

â Tf

where Tf is for the pure solvent and Tf

is for the mixture.

ÎT = (K

)(m ) ,

m = (

(mass of

solute, g )
)( ).

f f c

c molar

mass, g

mol â1

mass of

solvent, kg

7. Next question

(a) If you weigh 6.355 grams of copper, add concentrated nitric acid to dissolve it, and then dilute the solution to a total volume of 50 mL, how many moles of copper are in this solution?

(b) For the equilibrium reaction 3H2(g) + N2(g) â 2NH3(g), what is the equilibrium constant expression, Kc, for this reaction? (5pts)

8. Suppose at some temperature, the equilibrium concentration of H2 is 0.45M, the equilibrium concentration of N2 is 0.38M, and the equilibrium concentration of NH3 is 0.42M. What is the value of the equilibrium constant for the reaction 3H2(g) + N2(g) â 2NH3(g) at this temperature? (Show your work. No credit will be given if your work is not shown.)

9. Next question
(a) If you need 0.0534 moles of NaOH to reach equivalent point in the titration with acetic acid, how many mL of 0.09876M NaOH will you need?

(b) The Ksp of Cu(OH)2 is 2.2x10-20, what is the solubility of Cu(OH)2?

10. Next question
(a) In non-sulfide qualitative analysis of representative cations, the Group A cations comprising of Pb2+,

Hg2+, and Ag+ give a precipitate with solution.
(b) From a solution containing mixture of Pb2+, Fe3+, and Al3+, Pb2+ is removed by adding HCl solution. To the remaining cation mixture, on making the solution basic with NH3 (pH=9 â 10), both the cations form precipitate. Further analysis of the cation mixture containing Fe3+ and Al3+ is carried out by adding NaOH solution.

Aluminum hydroxide (dissolves/remains undissolved) in NaOH solution while Ferric hydroxide ( dissolves/remains undissolved).
(c) Fe(OH)3 precipitate is dissolved in minimal amount of aqueous HCl which gives a

yellow solution. To this solution addition of solution (at pH = 4 â 5) yields a dark blue solid known as Prussian Blue.

(d) Describe the method for checking for completeness of precipitate in qualitative analysis of ions.

CHE 1302 Lecture Notes - Lecture 12: Supersaturation, Molar Mass, Correlation Does Not Imply Causation

Document Summary

Get access

Related Documents

CHE 1302 Lecture Notes - Lecture 2: Intermolecular Force, Hydrogen Bond, Enthalpy

CHE 1302 Study Guide - Quiz Guide: Formula Unit, Colloid, Freezing-Point Depression

CHE 1302 Study Guide - Quiz Guide: Rate-Determining Step, Heterogeneous Catalysis, Fractional Distillation

Related Questions