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Physical Chemistry

Acid-base titration & analytical chemistry

A 0.213-g sample of uranyl(VI)nitrate, UO2(NO3)2, is dissolved in 20.0 mL of 1.0 M H2SO4 and shaken with Zn. The zinc reduces the uranyl ion, UO2 (with a charge of 2+), to a uranium ion, Un+ (where n+ is the charge of the uranium ion). To determine the value of n, this solution is titrated with KMnO4. Permanganate is reduced to

empirical formula and molecular formula

2) Two substances Q and R each have the elemental composition C = 60% h=13.3% 0=26.7% by mass 0.60 grams of each substance occupied a volume of 0.336 liters at 137 Celcius and standard pressure a) Calculate the empirical formula and the relative molecular mass of Q and R. B) What is the molecular formula

Physical Chemistry Questions

1) How many milliliters of 0.480M NaOH would be required to titrate a 5.00ml solution of 0.320M H2SO4? Report answer to the correct number of significant figures. 2) Write a balanced equation for the combustion of octane, C8H18. 3) If the standard enthalpy of formation (deltaHf) of methanol, CH3OH, is -238.6kJ/mol, deltaHf(CO

Rate of S(IV) to S(VI) at Different pHs using O3 and H2O2

If the ozone concentration in the plume is 80 ppb, calculate the liquid-phase rate of S(IV) oxidation in the plume by ozone. The rate for the oxidation of SO2 by H2O2 is given by the expression: please see attachment for expression. where k = 7.45  107 M-2 s-1 and K = 13 M-1. If the pH of the rainwater is 4.3, ca

Gaussian Plume-Qualitative

Explain qualitatively how the following would change the calculated surface concentration of SO2 assuming a gaussian plume from a smoke stack that follows the gaussian equation for the concentration of SO2 i) The wind speed decreased. ii) The wind speed increased. iii) A stable temperature profile became unstable. iv) An

Liquid Phase Oxidation of S(IV) to S(VI) and pH Lowering

Write the reactions responsible for the LIQUID PHASE oxidation of S(IV) to S(VI), and show how the oxidation can lead to a decrease in pH of rain water. I think you can help me with this. Please let me know. I've included all details.Thank you Dr. M. There are two sets of reactions with 3 parts for each set. I'm not sure w

Maximum buffer capacity: Example problem

The question is attached. Starting with equation (8.5) show that the maximum buffer capacity occur at pH=pKa. The units of buffer capacity are mol L^-1. As a consequence of the definitions, buffer capacity is always a positive quantity. For a monoprotic acid the buffer capacity (as a function of pH) is given by: (see attach

Colligative Properties/Phase Diagrams/Intermolecular Forces

Diagram and explain the H-Bonds if they exist for the following molecules: (a.)H2S, (b.)CH4, (c.)H2SO3, and (d) PH3. Give reasons for the fact that ionic solids as NaCl have high melting points and dissolve readily in water, whereas network solids such as diamond have very high melting points and do not dissolve in water.

Combustion of Sucrose in a Bomb Calorimeter

1. Combustion of 2.016 grams of solid sucrose (C6H12O6) at 25 º C in a bomb calorimeter with heat capacity 9550 J K -1 gives a temperature rise of 3.282 º C. a) Write the balanced equation for the combustion of sucrose b) What is the work done by the system? c) What is the heat change per mole of sucrose for the reaction?

Kinetic Molecular Theory of Gases Questions

1. Calculate the average kinetic energy of the N2 molecules in a sample of N2 gas at 273K and at 546K. 2. Consider separate 1.0 L gaseous samples of H2, Xe, Cl2 and O2 at STP. a) Rank gases in increasing kinetic energy. b) Rank gases in increasing velocity. c) How can separate 1.0 L samples of H2 and O2 have the same aver

Pressure and Temperature Determination

Suggest the pressure and temperature at which 1.0 mol of (a) Nh3, (b) Xe, (c) He will be in states that correspond to 1.0 mol of H2 at 1.0 atm and 25 degrees Celsius. NH3: T = 3.64 x 10^3 K, p= 8.7 atm, Xe: T=2.60K, p=4.5 atm, He: T=46.7K, p=0.18 atm.

equation of gas state leading to critical behavior

Please see attached file. A scientist proposted the following equation of state P = RT/Vm -B/Vm^2 + C/Vm^3 where B and C are independent of the temperatures. Show that the equation leads to critical behavior. Find the critical constants of the gas in terms of B and C and expression for the critical compression factor

Equilibrium Expression of a Buffer

If you add Na2CO3 with NaHCO3 and distilled water what is the equilibrium expression for the buffer? And what is the weak buffer and the conjugate base? What Ions are present in the solution?

DeltaG Values from Reactions and Non-standard Conditions

1) If the overall deltaG of the following reaction is -5.3Kcal/M and we know that the deltaG for the conversion of ADP + Pi ---> ATP is +7.3Kcal/M, what must the deltaG be for the conversion of PEP ----> pyruvate? Phosphoenolpyruvate (PEP) + ADP ----> pyruvate + ATP 2) Working in the lab, you determine the deltaG0 for t

Equilibrium Shift of a Reaction and the pH of a Solution

1. The pressure on each of the following systems is decreased from 5 atm to 1 atm. Which way does the equilibrium shift in each of the following systems? a.) 2CO2 (g) --> 2CO (g) + O2 (g) b.) H2 (g) + I2 --> 2HI (g) 2. What is the pH of a solution if the H+ concentration is 7.2 X 10^-14 M? Is this neutral, acidic, or ba

PH and molarity of pure water

You add 5 drops of .100 M HCl to 100ml of "pure" water. Assuming that the volume of one drop is .035ml, calculate the expected pH of the resulting solution. .

Finding the Final Temperature of a Solution

Urea, (NH2)2 (CO), is used in the manufacture of resins and glues. When 5.00 g of urea is dissolved in 250.0 mL of water (d=1.00 g/mL) at 30.0°C, 27.6 kJ of heat is absorbed. What is the final temperature of the solution in kJ? The density of water is 4.18 J/g·°C. What is the final temperature in °F? F = °C x 1.8 + 32 (Roun

heat realsed by combustion of ethyl ether

1. In earlier times, ethyl ether was commonly used as an anesthetic. It is, however, highly flammable. When 5.0 mL of ethyl ether C4H10 (l), (d=0.714 g/mL) is burned in a bomb calorimeter, the temperature rises from 23.5°C to 39.7. The calorimeter heat capacity is 10.24 kJ/°C. What is heat released when 5.00 mL ethyl ether is

Atomic Mass of Aluminum and Hydrogen Cyanide Balanced Equation

1. If 1 mole of Al4C3 has a mass of 144g and carbon has a mass of 12g, what is the atomic mass of aluminum? 2. Hydrogen cyanide (boiling temp 26 degrees) Write a balanced chemical equation using the lowest possible whole number coefficients, including the state of each compound. Reaction occurs at a temperature above 100 d

Calculating Mass and Moles

GIVEN INFO: from an unknown bottle: Unknown= #25 Metal present= Na Mass% metal= 43.88% Atomic masses: Cl= 35.453g O= 16.0g C= 12.0g H= 1.00g 1. Mass of crucible and cover= 32.493g 2. Mass of crucible, cover, and unknown=33.001g 3. Mass of crucible, cover, and solid chloride= 33.017g -----------------------------

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?

Thermochemistry

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

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