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Stoichiometry

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?

Picograms

Im confused on how to do this problem all together. I can't find help in the book because their answers are hard to follow. If you could work this out and explain how each step was done so I could understand how to do it that would be awesome. Thank you Given that the average TEQ of animal-based foods is about 0.7 picograms o

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

Molar concentration, solutes, and solvents

Calculate the molar concentration of a solution containing 4.75 of Ca(NO)3 in 0.200 L Calculate the volume of 2.00M Na3(PO)4 in milliliters that contains 6.80g of solute. How many grams of solute are present in 42.0mL of 0.200M K2Cr2O7 ? If 4.20g of (NH4)2SO4 is dissolved in enough water to form 400mL of solution

Find the concentration of the hydrogen peroxide solution.

Please see attached file for full problem description. 1. Find the concentration of the hydrogen peroxide solution. Doing an analysis of hydrogen peroxide using Potassium Permangate Equation is: 2KMnO4(aq)+5H2O2(aq)+3H2SO4(aq) -->5O(g)+K2SO4(aq)+2MnSO4(aq)+8H2O(l) Potassium Permangate is the titrant. Obtained a 1.00mL al

Example of Lab Report: Decomposition of Potassium Chlorate

Calculate and record the following for the experiment performed with 10.000 g KClO3 1. (a) mass of the crucible with manganese(IV) dioxide (in grams) = 53.300g (b) mass of the crucible after potassium chlorate has been added (in grams) = 63.300g (c) mass of the crucible after heating (in grams) = 59.383g (d) mass of po

Finding the Age of a Rock Using Radioactive Decay Data

(1) The half life of U-238 is 4.51x10^9 yrs. In a rock containing N atoms of U-238, how many Helium atoms are produced by radioactive decay of U-238 to Pb-206 in 4.51x10^9 yrs? (2) A rock is analyzed for its helium and uranium content and found to contain 1.00x10^-9 mole of U-238 atoms, and 2.00x10^-9 mole of Helium atoms. As

Concentration of Lead in Soil from Mine Tailings

Lead from mine tailings containing 0.6 % lead was applied at a rate of 12 metric tons per acre of soil and worked in to a depth of 20 cm. The density of the soil is 1.8 g/cm3. To what extent does this add to the burden of lead in the soil? (There are 640 acres per square mile and 1609 meters in a mile.) a) 19 ppb b) 45 ppb

Calculations required for a typical "Calculation of Gas Constant" lab report.

Example of Gas Law Constant Lab Report PLEASE SEE THE ATTACHED FILE FOR THE FULLY FORMATTED PROBLEM 1. A student performs the experiment according to the instructions in this experiment. (SHOW WORK in spaces provided) a. The weight of magnesium ribbon used is 0.0328 grams. How many moles of hydrogen could be collected

Chemical Reaction

What volume of 0.5 M H2SO4 is needed to react completely with 20.0 ml of 0.4 M LiOH?

Titre Calculations and Reactions

1. 20.0ml of calcium lactate solution was diluted with 30ml of water, to give a titre value of approximately 20ml of 0.05M disodium edetate. What would you expect the approximate titre value to be if the calcium lactate had been dissolved in 60ml of water? 2. How many moles of disodium edetate react with each mole of calcium

Synthesis of a chemical compound: Making alum from aluminum

How do I calculate the amount of alum left over in the following problem? Experiments show that solubility of alum in 25 mL of 1.4 M KOH plus 10 mL of 9M H2SO2 is about 1.0 g at 1.0 oC and 1.7 g at 6.0 oC. Using your measured solution temperature (4.5 oC) estimate the amount of alum left in your chilled solution

mass percent and volume percent of ethyl alcohol in solution

Ethyl alcohol, C2H6O is the alcohol present in liquor. A solution is made up by adding 25.0 mL of ethyl alcohol (d = 0.789 g/mL) to 45.0 mL of isopropyl alcohol, C3H8O (d = 0.7855 g/mL). Assuming volumes are additive, calculate the following: The mass percent of ethyl alcohol in the solution. Ethyl alcohol, C2H6O is

Energy Required to Produce

9. Find the energy required produce 1kg of Al from native Al2O3 and compare this with the energy required to melt 1kg of aluminum in a recycling plant.

If 42.50 ml of solution of 100grams

If 42.50 ml of solution of 100grams of potassium chromate per liter was used to completely react with a sample of 10 grams of soluble lead (II) salt, what is the percentage of lead (II) in the sample

Making a Buffer

How would I make a 10% NaCl 100ml buffer made up from a 5M NaCl stock solution. The NaCl stock is aqueous solution.

Calories from Fat

A person on a 2500-Cal low-fat diet attempts to maintain an intake of no more than 20% of food energy from fat. What percent of the daily fat allowance is represented by a tablespoon of peanut butter (15.0 g and 50.1% fat)? Fat has a food value of about 9.0 Cal/g. A. 14 % B. 27 % C. 2.7 % D. 0.17% E. 5.4 %

Iron Production in a Reaction

How many grams of iron can be produced from 3.50 Kg FeO3 from the following reaction FeO3(s) + 3CO (g)-------->2Fe (s) = 3CO2 (g)

Anaerobic Respiration with Ethanol

If the Density of Ethanol is 0.789 g/ml, Starting with 1.00 Kg of glucose, what is the maximum amount of ethanol in grams and liters that can be obtained by the process of the following reaction C6H12O6 (I)__----> 2 C2H5OH (I) + 2 CO2 (g)