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Stoichiometry

Electroplating : Mass of Copper and Silver on a Strip

Copper metal can reduce silver ions to metallic silver. The copper is oxidized to copper ions according to the reaction 2Ag^+(aq) + Cu(s) --> Cu^2+(aq) + 2Ag A copper strip with a mass of 2.00 g is dipped into a solution of AgNO3. After some time has elapsed, the copper strip is coated with silver. The st

Wet Limestone Process : Calcium Carbonate and Calcium Sulfate

Assume that the wet limestone process requires 1 metric ton of calcium carbonate to remove +50.0% of the sulfur from 4 metric tons of coal containing +5.0% S. Assume that the sulfur product is calcium sulfate. Calculate the percentage of the limestone (calcium carbonate) converted to calcium sulfate.

AgCl Solubility and Ksp

Suppose that a 20 mL sample of a solution is to be tested for the presence of chloride ion by the addition of 1 drop (.20 mL) 0.10M AgNO3. What is the minimum number of grams of chloride ion that must be present in order for AgCl to form?

Unknown Concentrations from Chromatogram

3) Solution 1 contains a ratio of 2.54 :1 pentanol to hexanol. When the chromatogram was run, the peak area of the pentanol was found to be 4,320, and the peak area of the hexanol was found to be 4,156. When an unknown was run, a solution containing 1.00 mL of the unknown pentanol was mixed with 5 mL of 1.42 mM hexanol, and the

Calculating Percent Yield

1.Sn(IV)4? -my experimental value was 0.194g and my melting point: 147 C - my balanced equation Sn + 2I2 -------> SnI4 - we used .24g of Sn, 0.95g I2 (I got 1.25 g as my theoretical value didn't look right so I need to double check) 2.Sn(II)I2? -my experimental value was 0.314g and melting point 160 C - balanced equa

Wavelength and Absorbace

1. What is the wavelength of an emission line for iron that has a frequency of 5.68×1014 Hz? 2. A solution of CoL3+ has a percent transmittance of 28.9 % at 565 nm in a 2.00 cm cell. The molar absorptivity for the complex at this wavelength is 2.45×104 L/(mol?cm). What is the absorbance of CoL3+ in this solution? 3.

Finding the Mass of a Plated Metal

Calculate how many grams of gold would be plated out on a coin, if a current of 2.3 (Amp) is applied for 15 min to an electrolytic cell shown above. The following reaction is occurring: Au^3+ + 3 e- → Au MW for gold equals 197g / mol. 1 amp (A) = 1 coulomb/second (C/s) Charge on 1 mol of electrons = 96500 coulombs

A Beginner's Guide to Calculating Density

This posting provides a general definition of density as well as two example to calculate density. The first example is based on finding the density of a cube by calculating the cube's volume. The second example is based on finding the density of an egg using the volume displacement method.

Reactions with Zinc Products

Find how many grams of zinc are produced when 500.00kJ of energy is evolved from the reaction of Cu II metal with zinc sulfide. (zinc blend) That should be balanced now. 2Cu + 2ZnS ---> 2CuS + 2Zn + 500.0 KJ Can someone give me advice or tell me what is not being understood. Full solution please.

Application of Archimedes' Principle to Determine Density.

A student gently drops an object weighing 15.8g into an open vessel that is full of ethanol, so that a volume of ethanol spills out that is equal to the volume of the object. The experimenter then weighs the vessel and its contents and finds that it weighs 10.5g more than the vessel when it was full of ethanol only. The density

Molecular Weights and Percent of Element by Mass

1. Calculate the molecular weight of the following compounds: Al2(SO4)3 ____________________ SbBr5 ____________________ Fe(NO3)3 ____________________ C9H11NO2 ____________________ 2. Calculate the number of moles in 25 grams of each of the following compounds: C9H11NO2 ____________________ Al2(SO4)3 _________

Precipitation Reaction: Mass of Ions Before Precipitation

A solution contains Cr3+ ion and Mg2+ ion. The addition of 1.00 L of 1.55 M NaF solution is required to cause the complete precipitation of these ions as CrF3 (s)and MgF2(s). The total mass of the precipitate is 50.2 g. Find the mass of the Cr3+ in the original solution.

Molecular Formula of a Gas

A gaseous hydrogen and carbon containing compound is decomposed and found to contain 85.63%C and 14.37%H by mass. The mass of 258 mL of the gas, measured at STP, was found to be 0.646 grams. What is the molecular formula of the compound?

Conversions and Dosage

Please see the attached file for the complete problems. Significant Figures in Calculations Part A Compute 3.5 * 4.48697 . Round the answer appropriately. Express your answer numerically using the proper number of significant figures. Part B Compute 1240.64/12.5. Round the answer appropriately. Express your answ

Concentration of ion after precipitation

46.36 ml of 0.5000 M AgNO3 is added to 270.00 ml of water which contains 5.832g k2CrO4. A red precipitate of Ag2CrO4 forms. What is the concentration, in mol/L , of UNPRECIPITATED Cro4 2- ? Must have correct number of significant figures. Assume AgCrO4 is completely insoluble.

Isotope Occurrence and Natural Abundance

Boron has only two naturally occurring isotopes. The mass of boron-10 is 10.01294 amu and the mass of boron-11 is 11.00931 amu. Use the atomic mass of boron to calculate the relative abundance (%) of boron-10, and the relative abundance (%) of boron-11. *I know the average amu for boron is 10.81. I don't understand how you so

Gasoline Composition To Produce Specified Oxygen Percentage

Calculate the mass percent of methanol, ethanol, and MTBE each that must be present in gasoline to yield a mixture of 2.9 % oxygen by weight. Hint given: Calculate percent oxygen in each compound. I don't have the density of the gasoline in the question or in the textbook. However, all I can find relevant in the textbook i

Fermi Energies of Fermi Gases

See attachment for full problem and symbols. Calculate the Fermi energies Eg (in units of eV) and the corresponding Fermi temperatures TF for: a. Liquid 3He (density 0.0823 g cm^-3) b. Electrons in aluminium (valence 3, density 2.7 g cm^-3) c. Neutrons in the nucleus of 16O. The radius r of a nucleus scales roughly as r =

Solubility, Concentration and Precipitation Problems

At 25 degrees C, the value of Ksp for PbCl2(s) is 1.6x10^-5 and the value of Ksp for AgCl(s) is 1.8x10^-10. 1) If 60.0mL of 0.0400 M NaCl (aq) is added to 60.0mL of 0.0300M Pb(NO3)2(aq) will a precipitate form? Assume that the volumes are additive. Show calculations to support your answer. 2) Calculate the equilibrium value

normality of solution

For each of the following solutions, the mass of solute taken is indicated, along with the total volume of solution prepared. Calculate the normality of each solution. (a) 0.139 g NaOH; 10.5 mL N (b) 11.5 mg Ca(OH)2; 100. mL N (c) 12.5 g H2SO4; 195 mL N

Toxicity of TCDD in Animal Based Foods

Given that the average TEQ of animal-based foods is about 0.7 picograms of TCDD equivalent per gram, and that the LD50 for 2,3,7,8-TCDD is about 0.001 mg/kg body weight, what mass(kg) of animal-based food would you have to consume to ingest a fatal dose of it?

Titration of Sulfhydryl Groups on an Enzyme

Many enzymes are inhibited irreversibly by heavy metal ions which react with essential sulfhydryl groups to form mercaptides. The affinity of silver ions (Ag+) for sulfhydryl groups is so great that it can be used to titrate -SH groups quantitatively. To a 10 ml of solution containing 10mg/ml pure enzyme was added just enough

calculation of molar concentration of salt with known Ksp

I need some clear and simple help on understanding how to calculate the molar concentration of an ion if the Ksp of the compound is known: I have 2 problems that I want to clearly understand: 1) Zinc hydroxide: --- if the Ksp for Zn(OH)2 is 1.2x10^-17 M and my solubility equation is: Ksp = [Zn] [OH]^2 --- how do I determi

SO2 Concentration Downwind from a Power Plant

4) A power plant burns 10^4 kg hr-1 of coal that contains 2.5% sulfur. The stack is 50 m high, and the plume typically rises 30 m. a) Calculate the ground-level concentration of sulfur dioxide (SO2) (in micrograms m-3) 800 m downwind from the source directly under the plume under the following conditions: Wind speed = 4 m s-1

Typical Titration/Neutralization Problems

What volume of 0.150M HClO4 solution is needed to neutralize 54.00mL of 8.80×10^-2 M NaOH? What volume of 0.120M HCl is needed to neutralize 2.78g of Mg(OH)2? If 25.0 mL AgNO3 of is needed to precipitate all the Cl- ions in a 0.785 mg sample of KCl (forming AgCl), what is the molarity of the AgNO3 solution? If 45.5