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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

Calculating Molarity of NH3

Calculate the molarity of a NH3 solution made up of 30.0 grams of NH3 in 70.0 grams of water. The density of the solution is 0.982 g/ml. Significant figures should be taken into effect.

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

Removing Lead Using Chloride Precipitate

You have a Lead (II) solution, and you want to remove the Lead by forming a Lead (II) chloride precipitate. How large do you have to make the chloride concentration at least to be sure that the amount of Lead left in solution is less than 0.28 mg/L? Express in mol/L.

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

Conversion

A wastewater sample was collected from the influent of a primary sedimentation tank. The following results were obtained from tests conducted on 50 mL wastewater samples. Determine total solids (TS), total suspended solids (TSS), and total dissolved solids (TDS). Tare mass of evaporating dish = 62.003 g Mass of eva

Precipitation of Calcium Oxalate

Calcium oxalate, CaC2O4, is very insoluble in water. What mass of sodium oxalate, Na2C2O4 is required to precipitate the calcium ion from 36.5 mL of 0.106 M CaCl2 solution?

mixture solution

If you have a 2 M stock solution of Tris Buffer, a 0.5 M stock solution of Magnesium chloride, and a bottle of crystalline sodium chloride. Use these reagents to make 500 ml of a solution containing 50 mM Tris, 5 mM of MgCl2, and 0.25 M sodium chloride.

Calculating moles

How do you calculate the number of moles of MgCl2 in 15g of MgCl26H2O?

Concentration of Glucose in Blood

On average, glucose makes up about 0.10% of human blood, by mass. What is the approximate concentration of glucose in blood in milligrams per deciliter?

Mass Percent

What is the mass percent of solute in each of the following solutions? a.) 155 mg NaCl/g solution b.) 0.242 L methanol (d= 0.791 g/mL)/kg water c.) 3.8 L ethylene glycol (d= 1.114 g/mL) in 6.5 L propylene glycol(d= 1.036 g/mL)

Mole fraction in a solution

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.)

Finding the Molality and Molarity

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.)

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 of 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.