How many milliliters of 1.27 M KOH should be added to 100. mL of solution containing 10.0 g of histidine hydrochloride (His·HCl, FM 191.62) to get a pH of 9.30?

In an experiment where you standardize EDTA with calcium carbonate and then have EDTA as the titrant and zinc as the analyte to determine the amount of zinc, which of the following are potential sources of error in the determination of the mean and relative standard deviation for the amount of zinc in your unknown?

Select all answers that apply.

1) Lack of homogeneity in the indicator solution

2) Not dissolving calcium carbonate completely

3) Inconsistencies in pipetting the zinc unknown

4) Systematic error in the buret calibrations

5) Failing to quantitatively transfer calcium carbonate

6) Sharing the indicator bottle

7) Over-titrating

Calcium Oxide (CaO) is widely used in the production of cement, steel, medicines and many other familiar materials. It is usually produced by heating and decomposing limestone (CaCO3), a cheap and abundant material, in a calcination process:

CaCO3(s) -> CaO(s) + CO2(g)

CaCO3 at 298 K is fed to a continuous reactor. The calcination is complete, and the products leave at 1000 K. Taking 800 gmol of limestone as a basis and elemental species [Ca(s), C(s), O2(g)] at 298 K as reference for enthalpy calculations.

Ccalculate the required heat transfer to the reactor in MJ.

Malonic acid (H2M) is a diprotic acid. You wish to prepare a buffer of malonic acid (pKa1 = 2.847, pKa2= 5.696) with a final pH of 2.90 but you only have disodium malonate (M2-) in your laboratory shelf. You dissolve 100 mmol of this salt in 1 L of water. Assume both dissociation processes are decoupled.

What is the initial pH of the solution? State any assumptions you make.

How many equivalents of strong acid must you add to your solution to end with only HM- ?

What is the approximate pH of this solution of HM- ? Use an adequate mathematical approximation.

How many additional equivalents must you add to reach the desired pH of 2.90?

Oliver likes to go fishing in the river by his house. One day he noticed that there was a white substance on some rocks at the bottom of the river. When he looked closely, it appeared as though someone had sprinkled a powder or crystals in the water. Moreover, the substance was found mainly where a small creek joined the larger river.

Curious, Oliver followed the creek through the forest toward an industrial area. Eventually, he reached a fence and found the source of the creek water — a large drainage pipe. Oliver noticed that there was steam coming off the water as it flowed out of the metal pipe.

The temperature reading (in ^oC) of the water that flowed out of the drainage pipe: 88.35

The temperature reading (in ^oC) of the water in the river: 7.14

Analysis at four differnt points along the creek and river revealed that the chemical potassium nitrate was found in the water.

1. Explain what is happening, in general terms, by applying your understanding of solutions and solubility.
2. Use the information provided to calculate the concentration of the solution in parts per million (ppm).
   • Point A: 14.7 g of KNO_3(aq) in 1.00 x 10³ L of H₂O_(l)
   • Point B: 1.12 g of KNO_3(aq) in 1.00 x 10² L of H₂O_(l)
   • Point C: 200 mg of KNO_3(aq) in 1.00 x 10² L of H₂O_(l)
   • Point D: 0.061 g of KNO_3(aq) in 1.00 x 10¹ L of H₂O_(l)

   Note that 1 ml of water has a mass of 1 g.

   In addition to potassium nitrate, analysis revealed there was four other chemicals found in the water at Point A.

3. Use the information provided to calculate both the molar mass and molarity for each chemical found in the water.
   • Sodium sulfate: 25.8 g of Na₂SO_4(aq) in 1.00 x 10¹ L of H₂O_(l)
   • Sodium carbonate: 582.2 mg of Na₂CO_3(aq) in 1.00 x 10² L of H₂O_(l)
   • Barium chloride: 6.8 mg of BaCl_2(aq) in 1.00 x 10³ L of H₂O_(l)
   • Magnesium phosphate: 212 g of Mg₃(PO₄)_2(aq) in 1.00 x 10¹ L of H₂O_(l)
   Potassium nitrate: 14.7 g of KNO_3(aq) in 1.00 x 10³ L of H₂O_(l)
4. The pipe used by the factory was made of an alloy of steel (Iron (Fe) = 90%, Carbon (C) = 8.5%, Manganese (Mn) = 1.5%). What amount (in kilograms) of each element was found in the pipe if it has a mass of 24.9 kg?
5. An alloy of gold contains 65% gold (Au), 16.5% silver (Ag), and some copper (Cu). What amount of copper would you expect in 59.8 g of this gold alloy?

How do you calculate the intrinsic viscosity of a polymer solution given only:

1) Time for a solution to go through a viscometer

2) Concentration

3) Viscometer constant

4) Density, viscosity, and time of water passing through a viscometer

I must calculate intrinsic viscosity and molar mass of cleaved and uncleaved PVOH solutions, but I am totally lost.

Let's say you are going to titrate a 200 ml solution of 0.5M KOH with a 0.1M solution of HNO3.

a) What is the initial pH?

b) Determine the pH when 300ml, 500ml, 975ml, 1000ml, 1005 ml, and 2000ml of the acid are added to the initial solution.

c) Sketch a rough titration curve.

3.36

On March 11, 2011, a massive earthquake and tsunami triggered a major disaster at Japan’s

Fukushima nuclear plant. A plume extending to the northwest of the site deposited significant amounts of iodine-131, cesium-134, and cesium-137 up to 30 miles away. Iodine-131 has an 8-day half-life and cesium-137 has a 3-year half-life. Determine how long it will take 99% of the iodine-131 and 99% of the cesium-

137 to naturally decay (you can learn about “U.S. Nuclear Power Safety One Year after Fukushima” by readin

g the report written by D. Lochbaum and E. Lyman, located on the web site of the Union of Concerned Scientists, http://www.ucsusa.org/publications/publications-nuclear-power.html)

How could solubility of an analyte impact its results in HPLC? How would the peak differ, for example? How would a more soluble molecule's peak differ from a less soluble one?

Also, what are the peak areas based on in HPLC? Why is one peak sharper and higher than another, for example? Does that relate to how well a molecule is retained by the stationary phase in the chromotography?

If you change the detection wavelength, how would the peak area of the same molecule change?

What does having a larger response factor mean in the internal standard method in HPLC? does it just relate just to the ratio of the two molecules?

write 3 paragraph on what you see could be the impact on the planet and society of this new approach to chemistry

Calculate the pH at 25°C of a 0.65 M aqueous solution of phosphoric acid (H3PO4). (Ka1, Ka2, and Ka3 for phosphoric acid are 7.5 × 10−3, 6.25 × 10−8, and 4.8 × 10−13, respectively.)

Please show how you do the quadratic equation. I am struggling with this in particular. Thank you!

A tank of acetylene gas (C2H2) contains 52.0lb of the gas and is at a pressure of 511.2lb/in.2 .
Express the pressure of the gas in atmospheres. 760 mmHg= 14.696 lb/in.2.

For the reaction shown, compute the theoretical yield of product (in grams) for each of the following initial amounts of reactants.
2Al(s)+3Cl2(g)→2AlCl3(s)

1) 7.7 g Al, 24.4 g Cl2

Express your answer using three significant figures.

2)0.230 g Al, 1.15 g Cl2

Express your answer using three significant figures.

How are Cu2+ and Bi3+ separated from Pb2+ and How can Bi3+ be separated from Cu2+?

Consider a titration involving 40.0 mL of 0.100 M ammonia , NH₃ (in an Erlenmeyer flask)with 0.100 M HCl (in a burette) to answer the next two questions.

NH₃ + HCl