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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

Titration of a Weak Acid with a Strong Base

Find the pH before, at, and after equivalence point of 35 ml of 0.15 M lactic acid with 0.18 M NaOH. This is all the information I was given on this problem and I am confused. I think the pKa for lactic acid is 3.86.

Using the Arrhenius Equation

The rearrangement of cyclopropane to propene has been studied at various temperatures with the following results. Rate constant, k (s-1) Temperature (K) 3.30 x 10-9 600 2.19 x 10-7 650 7.96 x 10-6 700 1.80 x 10-4 750 2.74 x 10-3 800 3.04 x 10-2 850 2.58 x 10-1 900 (a) From the appropriate plot of these data, determi

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

Survival of Fish in Freezing Water

Fish produce glycerol to survive the freezing waters of the Arctic. Determine the degree to which the freezing point of blood and other biological fluids is lowered with the help of glycerol. What is the ideal concentration range of glycerol required to achieve this?

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

Heats of Fermentation and Combustion of Glucose

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 atm. b) What fraction is the heat calculated in (a) of the am

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

Meaning, use and calculation of empirical formulas

In this introduction are given the explanation of how to find out an empirical formula if one has found out the chemical elements of an unknown substance and measured their ratio of masses. Also, it is described how one can calculate the ratio of masses from a given empirical formula. Two examples and the explanation of the pri

Physical Chemistry - Unit Conversions

Question 1: A sheet of aluminum foil has a total area of 1.000 ft^2 and a mass of 3.626g. What is the thickness of the foil in millimeters (density of AL = 2.699 g/cm^3)? Question 2: In water conservation, chemistrs spread a thin film of certain inert materials over the surface of water to cut down on the rate of evapo

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

Solving Thermochemistry Problems

A house is designed to have passive solar energy features. Brickwork incorporated into the interior of the house acts as a heat absorber. Each brick weighs approximately 1.8 kg. The specific heat of the brick is 0.85 J/g-K. How many bricks must be incorporated into the interior of the house to provide the same total heat capaci

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

Concentration : Dilution Problem

A student placed 18.5g of glucose (C6H12O6) in a volumetric flask, added enough water to dissolve the glucose by swirling, then carefully added additional water until the 100.-mL mark on the neck of the flask was reached. The flask was then shaken until the solution was uniform. A 60.0-mL sample of this glucose solution was di

Molality of a Solution and Solute Particles

What is meant by Molality of a solution and Solute particles? Define. How many solute particles are there in 1m solution containing these substances in one kg of water? a) Glucose b) Potassium chloride c) Ethylene glycol

Estimation of Mass Required in a Reaction

With the reaction, CaCO3+2Hcl->CaCl2+H2O+CO2. Using percent by mass what is the weight of HCl needed to react with calium carbonate? The weight of calcium carbonate that reacted with hydrochloric acid is 2.66.

Stoichiometry of Reactions

When a mole of C7H16 is combusted, it reacts with 11 moles of O2. How many moles of CO2 product are obtained? How many moles of H2O product are obtained? Also, I have another question: The production of aluminum metal from its ore is by the reaction: 2Al2O3 + 3C --> 4Al + 3CO2 How many grams of Al result when 775 grams o

Calculate mass, mole fraction and avg. molecular weight of air

Calculate the constituent (a) mass, (b) mole fraction (c)average molecular weight of air at 25 degree centigrade, 1 atm, and molar density of all listed gases is 24.5 L/mol, and volume air is given to be 100 L. Name Volume fraction N2 0.7808 O2 0.2095 Ar 0.0093 CO2 315

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

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