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Physical Chemistry

Buffers, Acids, Bases, Salts, Ka and Kb

QUESTION 1 Imagine that you are in chemistry lab and need to make 1.00L of a solution with a pH of 2.50. You have in front of you: - 100mL of 7.00x10-2 M HCl - 100mL of 5.00x10-2 M NaOH, and - Plenty of distilled water. You start to add HCl to a beaker of water when someone asks you a question. When you return t

Mass and Moles of Elements

To do this assignment, use your calculator to do the calculations required. Then invert the calculator to read the message word. Insert the message word into the appropriate space in the statement. Round off all atomic masses to the nearest whole number before using them. When handing in your assignment, be sure to show all

Using Equilibrium to Calculate Product

At low to moderate pressures, the equilibrium state of the water gas shift CO (g) + H2O (g) CO2 (g) + H2 (g) reaction is approximately described by the relation kp = (see attached file) The feed to a continuous shift reactor contains 30 mol% CO, 10 mol% CO2, 40 mol% water and the balance an inert gas. Th

Confirmatory Experiments : Freezing Point Depression and Solubility Tests

The purpose of lab this week is to do "comfirmatory experiments" that further explore the properties of your unknown compound and confirm that it reacts appropriately for the compound you predicted it to be at the end of lab last week. 1. Suppose your unknown is sodium acetate. When a solution of calcium chloride is adde

Heat Created by the Fermentation and Combustion of Glucose

Please help with the following physical chemistry problem: Alcoholic fermentation by microorganisms involves the breakdown of glucose into ethanol and carbon dioxide. C6H12O6 (s) -->; 2 C2H5OH (l) + 2 CO2 (g) a) Calculate the amount of heat liberated in a yeast brew upon fermentation of 1 mol of glucose at 25 °C and 1

Titration and Molarity Questions

Part A. Standardization of the 0.02 M KMnO4 solution with Fe(NH4)2(SO4)2 ? 6H2O. (Molecular weight of the ferrous sulfate hexahydrate is 392.16 g/mol). If you weigh out 1.01 g of the Fe(NH4)2(SO4)2 ? 6H2O, how many moles of iron (Fe+2) are in the sample? Part B Assume you fill a buret with your KMnO4 solution and the v

Molar Concentration of Copper (II) Nitrate

Please help with the following problem. Provide step by step calculations in this answer. A 25.00 mL sample containing Cu2+ gave an instrument signal of 23.6 units (corrected for a blank). When exactly 0.500 mL of 0.0287 M Cu(NO3)2 was added to this solution, the signal increased to 37.9 units. Calculate the molar concentrat

Heat Required to Convert Solid Benzene

The molar heat capacity of C6H6(l) is 136 J/mol x degrees centigrade and of C6H6 (g) is 81.6 J/mol x degrees centigrade. The molar heat of fusion for benzene is 9.92 kJ/mol and its molar heat of vaporization is 30.8 kJ/mole. The melting point of benzene is 5.5 degrees centigrade, its boiling point is 80.1 degrees centigrade and

Acid-Base Equilibria : Concentrations and pH

[OH-] and the pH for each of the following strong base solutions: -- 0.082 M KOH -- 1.065 g of KOH in 500.0 mL of solution -- 10.0 mL of 0.0105 M Ca(OH)2 diluted to 500.0 mL -- a solution formed by mixing 10.0 mL of 0.015 M Ba(OH)2 with 40.0 mL of 7.5x10-3 M NaOH

Titrations: Finding Mass Percent of Arsenic in a Pesticide

The arsenic in a 1.0211-g sample of a pesticide was converted to H3AsO4 by suitable treatment. The acid was then neutralized and exactly 40.00 mL of 0.05922M AgNO3 was added to precipitate the arsenic quantitatively as Ag3AsO4. The excess Ag+ in the filtrate and in the washings from the precipitate was titrated with 14.76 mL o

Gases : Partial Pressures

3.00 g of SO2(g) is originally in a 5.00 L vessel at 21 degrees Celsius and is transferred to a 10.0 L vessel at 26 degrees Celsius. 2.35 g N2(g) is originally in a 2.50 L vessel at 20 degrees Celsius and is transferred to the same 10.0 L vessel. - what is the partial pressure of SO2(g) in the larger container? - what is th

Oxidation Numbers (Oxidation States)

How do I find out the oxidation numbers of: - Ti in TiO2 - N in N2H4 - Cr in Cr2O7 2- <-- the 2- is above the margin, in the same place as if it was to the power of 2- - N in HNO2 - C in C204 2- <-- same as the Cr2O7 - Sn in SnCl3 - <-- same as others, possible -1?

Acid-Base Reactions: Names to Formulas from acid base reactions

What would be the proper balanced molecular and net ionic equations for each of these neutralization reactions? - solid chromium (III) hydroxide reacts with nitric acid - aqueous hypochlorous acid and aqueous calcium hydroxide react - aqueous acetic acid is neutralized by aqueous potassium hydroxide

Isothermal expansion

An ideal gas expands isothermally from state A to state B at 300K with an entropy change (deltaSsys) of 50 J/K. When the expansion was performed, the work done by the system was - 6 kJ/K. Was this process reversible or irreversible? Explain.

Convert to mg/L from Molarity

Convert to mg/L using dimensional analysis: 1. 0.01 N Ca+2. Here is additional info: salt is CaCl2 2. 1M HCO3 3. 0.02 N H2SO4 4. 0.02 M SO4 2- (i.e)sulfate ion

Determine Density (unit conversion)

Determine the density of liquid methanol in (lb/ft^3) and convert heat capacity, thermal conductivity and viscosity from SI units to English Units. Given: Specific gravity= 0.92 at 60 degree F Density of reference substances (Water)= 62.3 lb/ft^3 Heat capacity=0.61 cal/(gram degree centigrade) at 60 degree F Thermal Condu

Molecules of air exhaled

Total mass of the atmosphere is equivalent to that in a layer 7 kilometer deep with density equal to the density at the surface. Assuming that air is uniformly mixed, how many molecules of air you have exhaled in the last 20 years will be inhaled in a single breath? Given: Earth's surface area=5.11*10^9 square kilometers Vo

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. 1. Give the chemical formula for calcium phosphate. 2. A hypothetical element, Js, has three naturally occurring isotopes. The atomic mass and relative abundance of each isotope are: 35% 191 Js, 20% 18

Gasoline in a tank. To determine pressure etc.

The gasoline storage tank is filled to 12m and the closed space above is filled with nitrogen gas N2. For the condiction shown (see attachment) determine : a) Pressure of nitrogen gas b) Density of gasoline c) Force on the tank bottom d) Force on the flat door e) Minimum force to hold door closed

Energy Changes Due to Pressure and Temperature Changes

1. a volume of 20 cu ft of air at pressure of 50 psig is heated and expanded to 30 cu ft and 40psig find the change in the energy of air in joules. (A)35564 j (B) 48219 j (C)123378 j (d)167278j 2>A quantity of gas equal to 35 cu ft is to be expanded adiabatically.It has specific heat at constant pressure of 0.532 and

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