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# Physical Chemistry

### Calculate the work done (in Joules) when 33.3g of tin dissol

Calculate the work done (in Joules) when 33.3g of tin dissolves in excess acid at 1.04 atm and 22 degrees C. Assume ideal gas behavior. Sn(s) + 2H(aq) yields Sn2+(aq) + h2(g) I realize the equations PV=nRT and w=-p (change V) but have converted and can't seem to get it right?

### Energy in chemical reactions

See the attached document and find the heat of reaction for each set of reactions. Reaction 1: Heat of Dissolution of NaOH Reaction 2: Heat of Reaction Between Aqueous NaOH and Aqueous HCl Reaction 3: Heat of Reaction Between Solid NaOH and Aqueous HCl Questions: 1. Write the net ionic equation for each reaction,

### Macromolecules (dendrimers)

Discuss synthesis on dendritic macromolecules (dendrimers)?

### Molecules and Ideal Gas Law

1. A cylinder contains a mixture of hydrogen and chlorine molecules. Compare without doing any calculations: a) the relative mass of the molecules b) the temperature of each gas c) the average kinetic energy of the molecules d) the average speed of the molecules. 2. Find the number of atoms in a) 52.5g of calcium metal

### After losing the electron, how many protons will Na have in its nucleus?

Sodium (Na), atomic number 11, has a tendency to lose an electron in the presence of chlorine. After losing the electron, how many protons will Na have in its nucleus?

### Molarity of Bromophenol Blue Stock

You have 20 ml of 10% Bromophenol Blue (BPB). Using a 10% stock, how would you prepare 5 ml of a 0.2 % stock? (MW BPB is 670) Assume 1 % = 1 g/100ml. In addition, what is the molarity of the 0.2% BPB Stock?

### pH and Temperature

The dissociation of water increases as the temperature is raised: H20 --> H+ + OH-. If you adjust a buffer to pH 7.4 at room temperature (25 degree Celsius), then cool it down to 4 degree Celsius for an enzyme assay, will the pH increase or decrease?

### Buffer HEPES and MES got mixed. Identify which beaker contains HEPES.

You and a lab parnter prepare buffers to use in an experiment. Your partner prepares 200 ml 50 mM MES pH 6.0 while you prepare 200 ml of 50 mM HEPES pH 6.0. (MES and HEPES are the abbreviated names for two biological buffers often used in research labs). HEPES has MW 238.3 and pK = 7.48 MES has MW 195 and pK = 6.1 1. How

### PH and Molar Solubility

PH and Molar Solubility. See attached for full problem description. 12. What is the pH of a 650 mL solution that contains 250g of HNO2 and 100g NaNO2? 13. What is the molar solubility of MnCO3 if 5.3 x 10^-5 M Na2CO3 is added to the solution? 14. What is the pH of a solution after titrating 200mL of 0.100 M NH2OH to

### pH Determination After Titration

6. What is the hydrogen ion concentration of a solution with a pH = 4.54? a. 2.9 x 10^-19 b. 1.1 x 10^-2 c. 7.8 x 10^-5 d. 2.9 x 10^-5 e. 3.5 x 10^-10 16. What is the pH of a solution after titrating 25.0 mL of 0.500M HCOOH with 15.0 M of 0.500 M NaOH? a. 8.78 b. 3.57 c. 3.91 d. 10.43 e. 5.22 17. What is the pH

### pH Determination of Solutions

I need some help determining pH of these questions: 8. What is the pH of an 8.61 x 10^-4 M solution of the weak acid, HOCl? a. 10.52 b. 5.26 c. 4.80 d. 7.46 e. 3.06 9. What is the pH of an 8.45 x 10^-4 M of HBr solution? a. 3.07 b. 7.08 c. 1.54 d. 10.93 e. 6.92 10. What is the pH of an 1.25 x 10^-3 M solution o

### Percent by mass calculation

6. Assume that coal can be represented by the formula C135H96O9NS What is the percent of nitrogen by mass in this coal? If three tons of coal were burned completely, what mass of nitrogen in NO would be produced. Please show calculations. 7. This unbalanced equation represents the las step in the production of pure sil

### Chemistry Questions

1. Which of these has the lowest concentration of hydrogen ions: 0.1 M HCL 0.1 M NaOH 0.1 M H2S04 pure water. Explain your answer 2. One reagent bottle on the shelf in a laboratory is labelled 12 M H2SO4 and another is labelled 12 M HCL A. How does the number of moles of H2S04 in 100 ml of 12 MH2SO4 solution comp

### Calculating Delta S for reaction

1. At two different temperatures, the reaction A & B is allowed to reach equilibrium and Delta H is measure. Delta H =10.9 kJ/mol for this reaction at 5.5 C and Delta H=31.0 kJ/mol at 80.1 C. Calculate Delta S for this reaction at each of these two temperatures. (Hint Delta G = 0 at equilibrium).

### Standard free energy change for reactions

1. The Standard free energy change for the following reaction is -33.2 kJ/mol and the equilibrium constant Kp=6.59x105 at 25 C. N2(g) + 3H2 (g) <- -> 2NH3 (g) In a certain experiment, the initial pressures are P(H2)=0.25 atm, P(N2)= 0.87 atm and P(NH3)=12.9 atm. Calculate Delta G for the reaction at these pressures and pre

### Predicting Reactions and Calculating Quantity

Predict whether the following reaction would proceed spontaneously as written at 298 K by calculating both Delta G and e for the reaction, given that [Co2+] =.15 M and [Fe2+]= 0.68 M. ( E1/2= -0.282 for Co2+ + 2e- -----> Co0) Co0 + Fe2+ ---> Co2+ + Fe0 A current of 0.452 A is passed through an electrolytic cell co

### molarity of solution

1. Calculate the molarity of the following solutions from this acid-base titration data: a. If 250 ml of Ba(OH)2 of unknown concentration with a methyl red indicator present is titrated with [0.325 M] HNO3, the yellow solution turns red after 36.4 ml of the HNO3 is added. What is the molarity of the Ba(OH)2 solution? b.

### Chemistry Help

1. How many grams of CO2 would be formed from 20 grams of C8H10 in the following (UNBALANCED) reaction? C8H10 + O2 --> CO2 + H2O 2. How many moles of CO2 would be formed from 40 grams of CaCO3 in the following (UNBALANCED) equation? CaCO3 + HCl --> CaCl2 + CO2 + H2O 3. A gas sample has an original volume of 700 ml when

### Relative Uncertainty in Analytical Chemistry

Analytical Chemistry. See attached file for full problem description. Please answer questions 1, 4, and 5.

### Analytical Chemistry Calculations

6. A solution of Al2S3 is converted, by chemical means, to a form which can be precipitated as BaSO4. Calculate the gravimetric factor which allows determining BaSO4 from a sample of Al2S3. 7. What pH is required to just precipitate iron (III) hydroxide from a 0.10 M FeCl3 solution? Ksp for FE(OH)3 is 4 x 10^-38. 8. Calcul

### Calculate the molar mass of geraniol

See attached file for full problem description. 1. The volatile organic compound geraniol, a component of oil of roses, is used in perfumery. It was found that the density of the vapor at 260ºC is 0.480 g/L when the pressure is 103 Torr. Calculate the molar mass of geraniol. 2. consider the following apparatus. Calculat

### Isopentane Questions

(a) The molar volume of isopentane (C5H12) is 1.00 L at 503 K and 30.0 atm. (i) Does isopentane behave like an ideal gas? Justify your answer. (ii) Given that a = 17.0 L^2.atm/mol2 and b = 0.136L/mol calculate the pressure of isopentane as predicted by the van der waals equation. (b) The elements of group 5A, the nitro

### Heat Engine, Net Work, Waste Heat

An inventor claims to have developed a heat engine that receives 750 kJ of heat from a source at 400K and produces 250 kJ of net work while rejecting the waste heat to a sink at 300K. Is this a reasonable claim? Why?

### the appropriate PK of the weakest acid or base

What is the appropriate PK of the weakest acid or base that can be titrated in aqueous solution?

### Titration of a Strong Acid

Procedure 1 (click to view assignments for this procedure) PLEASE NOTE: Titration requires several steps in order to obtain exact results. 1. Take a clean Erlenmeyer flask from the Glassware shelf and place it on the workbench. 2. Add 25 mL HCl (of unknown concentration) to the flask. 3. Add 2 drops of phenolphthal

### Using ideal gas law to solve surface tension problem

Surface tension/Relative adsorption. See attached file for full problem description.

### How many milligrams of iron are in the sample

How many milligrams of iron are in the sample? See attached file for full problem description.

### Titration and Oxidization Problems

Titration and Oxidization. See attached file for full problem description.

### Solutions, Solubility and Concentration

18. The chloride in a 0.12-g sample of 95% pure MgCl2 is to be precipitated... Solutions, Solubility and Concentration. See attached file for full problem description.

### acid base titration.

See attached file for full problem description. 13. A hydrocholoric acid solution is standardinzed by titrating 0.4541 g of primary stardard tris(hydroxymethyl)aminomethane. If 35.37 mL is required for the titration, what is the molarity of the acid? 15. A sodium hydroxide solution is standardized by titrating 0.8592 g of