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# Physical Chemistry

### pH and molar concentration of hydrogen ion

1.Given the molar concentration of hydrogen ion [H+] = 6.2 x 10 -7, calculate the concentration of hydroxide ion. 2.Given the molar concentration of hydroxide ion [OH -] = 4.6 X 10 -13, calculate the concentration of hydrogen ion. 3. In 1 mL of water there are 3 X 1022 molecules of H2O. How many hydrogen ions are in 1 mL o

### Empirical Formulation of a Compound

16. A compound contains 40.00% carbon, 6.67% hydrogen, and 53.33% oxygen. Determine the empirical formula of the compound. Please help with the following problems. 1. Give the chemical formula for calcium phosphate. 2. A hypothetical element, Js, has three naturally occurring isotopes. The atomic mass and relative abunda

### Ideal Gas Equation: Pressure in atm of given quantity of gas

What is the pressure in atmospheres of 201 grams of O2 gas in a 12.0 liter vessel at 25.0OC?

### Determine the concentrations of hydronium and hydroxide ions in 0.0403 M aqueous sodium hydroxide.

4.) Determine the concentrations of hydronium and hydroxide ions in 0.0403 M aqueous sodium hydroxide. Kw = 1.0E-14. A.) Hydronium ion concentration?(answer in M) B.) Hydroxide ion concentration?(answer in M) 6.) Concentrated aqueous HClO4 has a concentration of 14.8 M. Calculate the concentrations of all ions present in a

### Expansion of Nitrogen - Ideal Gas Law

A sample of nitrogen gas has a volume of 3.00 L at 25 degrees C. What volume will it occupy at each of the following temperatures if the pressure and number of moles are constant: a) 546K b) 273K c) 373K

### 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 &#61620; 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

### Percent Yields and Limiting Reagents : NiCl2.6H2O + Ethylenediamine ---> Ni(en)3 Cl2

Some backround data: mass of NiCl2 + 6H2O = 3g mass of Ethylenediamine used: 2.85g initial moles ethylenediamine: .0474 (I think) product formed: mass of Ni(C_2_H_8_N_2_)_3_CL_2_: 3.597 The questions I need answered: -theoretical moles of product, based on stoichiometry. -molecular mass of product -theoretical mass o

### 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. .

### Neutralization of acetic acid: Example problem

Describe the rate limiting step; Give a practical every day example of this process and provide web site

### 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