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Physical Chemistry

Calculating Volume, Pressure & Density

1. A sample of CO2 gas at 22°C and 7.71 atm has a volume of 6.0 L. If the pressure decreases to 5.42 atm, what is the volume? (Round your answer to one decimal place) 2. 120 mL of ethyl alcohol, C2H5OH, is poured into a soft drink bottle at room temperature. The ethyl alcohol weighs 32.4 g and the bottle is heated to 100°C.

Chemical Reactions: Physical Chemistry

1. Some sulfuric acid is spilled on a lab bench. It can be neutralized by sprinkling sodium bicarbonate on it and then mopping up the resultant solution. The sodium bicarbonate reacts with sulfuric acid as follows. 2 NaHCO3(s) + H2SO4(aq) Na2SO4(aq) + 2 H2O(l) + 2 CO2(g) Sodium bicarbonate is added until the fizzing due to th

Chromate-dichromate equilibrium.

See attached file for full problem description. 1. How does the (H+) of the solution affect the CrO42-/Cr2O72- eqiuilibrium? 2. What poof was shown that CrO42- ions exist in a solution of K2Cr2O7. 3. In what way does OH- affect the equilibrium? Give two methods by which this ion upsets the equilibrium? 4. Write the e

pH of Solution During Titration Process

Q1: What is the pH of a 0.35 M solution of a weak acid HA with Ka = 1.41×10^-8? Q2: A 25.0 mL sample of the acid is titrated against 1.9 M NaOH. What is the pH after 5.0 mL of the base has been added? Q3: What is the pH after 10.0 mL of base has been added? Q4: What is the pH when 30.0 mL of base have been added?


Glauber's salt, sodium sulfate decahydrate (Na2SO4 * 10H2O) undergoes a phase transition (that is melting or freezing) at a convenient temp of 32 degrees C Na2SO4 * 1o H2O(s) yields Na2SO4 * 10 H2O(l) Change H = 74.4 kJ/mol As a result this compound is used to regulate the temperature in homes. It is placed in pl

Thermochemistry Reaction Completion

Consider the reaction: H2(g) + Cl2(g) yields 2HCl(g) Change Heat = -184.6 If 6.00 moles of H2 react with 6.00 moles of Cl2 to form HCL, what is the change in kJ for this reaction at 1.0 atm and 25 degrees C. Assume the reaction goes to completion.

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,

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

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

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?