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# Stoichiometry

### mole fraction of naphthalene in C6H6

What is th mole fraction of naphthalene, C10H8, in a solution prepared by dissolving 32.8 g C10H8(s) in 314 g C6H6(l)? (Use correct significant figures.)

### the molarity and molality of acetone solution

An aqueous solution is prepared by diluting 3.30 mL acetone, CH3COCH3, (d=0.789 g/ml) with water to a final volume of 75.0 mL. The density of the solution is 0.993 g/mL. What are the molarity and molality of acetone in this solution? (Use correct significant figures.)

### An analytical chemist determines that an estuarine water sample contains 1.5 g/L of sulfate ion.

5. An analytical chemist determines that an estuarine water sample contains 1.5 g/L of sulfate ion. What is the concentration in terms of (a) g/L of S (b) molar concentration of sulfate (c) normality (d) parts per million of sulfate.

### Assume that due to dwindling supplies of crude oil and natural gas, the US embarks on a plan to implement the "hydrogen economy"

Could you please explain what formula and step are involved and please provide (example) problem if possible Assume that due to dwindling supplies of crude oil and natural gas, the US embarks on a plan to implement the "hydrogen economy" for which hydrogen will be generated by electrolysis of water. The source of electricity

### Finding the Mass of Potassium Sulfite

What is the mass of 3.25 moles of potassium sulfite and how do I figure this out?

### molecular formula and empirical formula of the hydrocarbon

Complete combustion of a 0.0100 mol sample of a hydrocarbon, CxHy, gives 1.792 L of CO2 at STP and 1.261 g of H2O (a) What is the molecular formula of the hydrocarbon? (b) What is the empirical formula of the hydrocarbon?

### 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

### Graham's Law and Stoichiometry Problems

Question #1 C2H2Br4 + 2Zn ----> C2H2 + 2ZnBr2 How many grams of ZnBr2 are produced from 125g of C2H2Br4? Formula Weights are, H=1.01 C=12.0 Zn=65.4 Br=79.9 Question #2 Which gas molecules diffuse faster, NH3 (ammonia) or C3H8(propane)? Why? Whose Law is applied here?

### concentration mixture solution

Calculate the final concentration if a) 1.50L of 2.00 mol/L LiCl, 2.00L of 1.50 mol/L LiCl are mixed b) 1.50L of 2.00 mol/L LiCl, 2.00L of 1.50 mol/L LiCl and 4.00L of water are mixed. Please show work.

### Density of Silver from fcc Unit Cell and Atomic Diameter

Silver has a face-centered unit cell. The diameter of a silver atom is about 2.90 angstroms. Use this measurement to calculate the density of silver (grams per centimeter cubed)

### Empirical Formula Lab Report: CuSO4.5H2O and CuO ( Copper (II) Sulfate Pentahydrate and Copper (II) Oxide )

1. Data (a) mass of copper powder used (g): 25g (b) mass of copper powder and beaker (g): 72.420g (c) mass of copper oxide and beaker (g): 78.714g 2. Calculate the following for the copper: (a) The number of moles of copper powder, given a molecular weight of copper equal to 63.55 g/mole. (1 pt) {Convert

### 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

### Determining an empirical formula given the mass of an element and its oxide.

A mass of 1.40 g of nitrogen is reacted to form 3.80 g of oxide. What is the empirical formula of the oxide?

### 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

### Dissolving calcium carbonate into a solution of calcium nitrate

How many grams of CaCO3 will dissolve in 2.2 x 10^2 ml of 0.050 M Ca(NO3)2 ?

### 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 %