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Stoichiometry

An analysis of a wet sludge sample on a ppm weight basis indicates a value of 2900 ppm. The sample has a dry solids content of 19% (by weight) or a moisture content of 81% (by weight).

An analysis of a wet sludge sample on a ppm weight basis indicates a value of 2900 ppm. The sample has a dry solids content of 19% (by weight) or a moisture content of 81% (by weight). I have seen numerous computations including: ppm dry = ppm wet/% solids or, ppm dry = ppm wet/% moisture content Which is correct....

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.

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 _________

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

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

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

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

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

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 %

Mole, Empirical and Stoichiometry Calculations

Mole Calculations (Determining Avogadro's Number): 1. Calculate the mass of carbon in a diamond that contains 3.33 x 1024 atoms of C. 2. Calculate the mass of chloroform that contains 1,000,000,000,000 molecules of CHCL3. 3. Calculate the number of NaCL formula units in 1.37 g of table salt. 4. Calculate the number of N2 mo

Chemistry

A car gets 9.2 kilometers to a liter of gasoline. Assuming that gasoline is 100% octane (C8H18), which has a density of 0.69 g/cm3, how many liters of air (21% oxygen by volume at STP) will be required to burn the gasoline for a 1250-km trip? Assume complete combustion.

Balanced chemical equation for biosynthesis

Please help with the following problem. Write the balanced chemical equation for the biosynthesis of ethanol. Label the sucrose and the ethanol in the equation. If you start with one mol sucrose, how many mol ethanol is produced? (Assume complete conversion of sucrose to ethanol.) The density of ethanol is 0.80 g/ml. A

Molecular Weight by Freezing Point Depression of Solution

A 0.573g sample of a nonvolatile solute is added to 15.6g of napthalene and the mixture warmed until melted. The freezing point of the solution was determined and found equal to 78.1C. The freezing point of naphthalene is 80.2C. How do you find out if the boiling pt and the vapor pressure increases or decreases? How do you

Gas Laws - Volume, Density, and Temperature

1.) The density of liquid nitrogen is 0.808 g/mL at -196 degrees Celsius. What volume of nitrogen gas at STP must be liquefied to make 10.0 L of liquid nitrogen? 2.) Calculate the volume occupied by 2.5 mol of an ideal gas at STP. 3.) A hydrocarbon (compound containing only hydrogen and carbon) was analyzed to be 85.7 mass per

Percent by mass composition

While chlorofluorocarbons (CFC) are compounds that seem incredibly useful in industry, they also seem to wreak havoc on the ozone layer. If CFC-211 has a percentage by mass of chlorine of 80.46% and carbon of 10.90%, the rest being fluorine, what is the likely formula for CFC-211?

Forces in gases and in deep space

1.) How much force is required to inflate a high pressure bicycle tire to 95 pounds per square inch (655 kPa) with a hand pump that has a plunger with an area of 5.0 cm^2? 2.) An object exerts a force of 500. N and sits on an area of 4.5m X 1.5m. Calculate the amount of pressure exerted by the object in torr. 3.) During your t

Chemicals and Temperature

1. How small a change temperature can be detect by touch? How could smaller changes in temperature be detected? 2. What would be expect to observe if KHCO3 reacted with HBr? What test would be performed to identify the product? 3. If a reaction called for a minimum of 0.5 moles of table sugar, C6H12O6, and there was only o

Questions of density and volume

In my lab I determined volumes for two unknown metals by two different methods (displacement in a liquid: V=9ml vs. calculation of all sides: V=8.83 cm3 V=5ml V=4.75 cm3 The volumes are not the same. Which do you believe to be more accurate? Why?

Density Comparison of Masses

1. The density of an uncooked egg is much less than that of a hard boiled egg. Would it make any difference in this demonstration if the egg was hard boiled? If yes, explain what you would see if the graduated cylinder contained: a) only water b) only salt water c) 1/2 water, 1/2 salt water 2. Would a comparison of a can (

Density of Metals

1. Which is more dense, lead or brass? How it can determine? 2. A sheet of metal has the dimensions 5mm, 25 cm, 55cm and its mass is 14.7kg. Using the densities of metals, can you definitely tell what metal this is? How?

Understanding molar concentrations/volume /equations

1. molar concentration of a liter solution of HCl that has 65 grams of HCl in it? 2. How many grams of NaCl are needed to make a molar solution of 2 liters? 3. How many grams of a glucose are in 1 liter of 10% mass/vloume glucose solns?