Question

In: Chemistry

10. How would you carry out the following analysis? Give all the necessary steps required and...

10. How would you carry out the following analysis? Give all the necessary steps required and also mention your choice of instruments.

a. Hg contamination in a river

b. Parts per trillion level of Pb in drinking water

c. PAH in river water.

d. Gasoline contamination in ground water.

Expert Solution

a. Hg contamination in river

The water sample containing mercury is dugested with sulphuric acid - potassium permaganate solution to obtain free mercury ions. excess permaganate is removed my adding hydroxylamine and reducing with stannous chloride.

determination is done using Atomic Absorption Spectroscopy:

1. standard solution of mercury is prepared and standard curve is obtained.

2. now take absorbance of the sample and calculate the concentration.

standard curve is calculated by : y =mx +b where y is g Hg, x is area, m is slope and b is intercept.

calculate m and b.the calculate g mercury in sample and divide by sample weight in grams to obtain ppm.

----------------------------------------------------------------------------------------------------------------------------------------------------------------------

b. parts per trillion level of Pb in drinking water

1. standard of lead nitrate was preparedin de-ionized water. the series of standard sample was mixed with dithizone solution and then CTAB ( cetyltrimethylammonium bromide ). this mixture is diluted and absorbance is measured at 500nm against blank.draw calibration graph.

2. take absorbance of sample (unknown) and then plot absorbance in standard curve.

calculate concentration by :

-----------------------------------------------------------------------------------------------------------------------------------------------------------------

c. PAH in river water

The standard was used as Chrysene solution and the extract was analyzed in UV-Fluoroscence spectroscopy at 310 nm excitation wavelength and intensitis were measured at 360nm.

---------------------------------------------------------------------------------------------------------------------------------------------------------------------

d. Gasoline contamination in ground water

queen_honey_blossom answered 2 years ago

7. How would you carry out the following analyses? Describe the necessary sample preparation steps and...

7. How would you carry out the following analyses? Describe the necessary sample preparation steps and your choice of appropriate analytical instrumentation: a. Simultaneous determination of Pb, Zn, Cr, and Cd in crops grown in soil treated with sewage sludge. b. Determination of pesticide residues in apples. c. Determination of Pb in human plasma. d. Determination of SO4-2, NO3-, and PO4-3 in compost to be used for lawn fertilizer. e. Screening for gasoline contamination around underground storage tanks. f. A...

Explain how you would carry out a sensitivity analysis for this Leslie matrix model

Indicate how you would carry out each of the following reactions. How would you distinguish between...

Indicate how you would carry out each of the following reactions. How would you distinguish between the starting material and product by IR? Your answer should include both disappearance as well as appearance of IR absorptions. A) 1-methylcyclohexene to trans-2-methylcyclohexanol B) cyclohexene to cis-1,2-cyclohexandiol C) 1-hexyne to 2-hexanone D) 1-hexyne to 1-hexene E) 3-chloropentane to 2-pentene

Carry out (show all steps) the test to answer each of these questions. You may use...

Carry out (show all steps) the test to answer each of these questions. You may use either the classical method or the P -value method, but you must state the P -value for each problem. 3. A random sample of 15 households in a small city gives the following number of hours of television watched in one week. A marketing firm wishes to determine whether the mean amount of television watching per week is more than 8 hours at the...

Using the steps of interdisciplinary analysis, how would you construct an integrated, comprehensive analysis of the...

Using the steps of interdisciplinary analysis, how would you construct an integrated, comprehensive analysis of the impact of information technology on society? Consider, for example, the effects of age on Internet use. Do you think that younger people, who have grown up using the Internet, know how to use it to build community? Do older people find it more isolation? Explain

You are an oncologist required to treat a solid tumour. Outline steps on how you would...

You are an oncologist required to treat a solid tumour. Outline steps on how you would use your knowledge of cell cycling to achieve this.

Describe the components of a HPLC. How would you improve the accuracyof the analysis, if necessary?

You are required to carry out the computer networking of five (5) work stations. With the...

You are required to carry out the computer networking of five (5) work stations. With the aid of a well labelled, neat diagram, show how the networking components are interconnected and produce the bill of engineering measurement and evaluation for the job.

An iron wire has a cross-sectional area of 5.70 ✕ 10−6 m2. Carry out steps (a)...

An iron wire has a cross-sectional area of 5.70 ✕ 10−6 m2. Carry out steps (a) through (e) to compute the drift speed of the conduction electrons in the wire. (a) How many kilograms are there in 1 mole of iron?____ kg/mol (b) Starting with the density of iron and the result of part (a), compute the molar density of iron (the number of moles of iron per cubic meter). _____mol/m3 (c) Calculate the number density of iron atoms using...

An iron wire has a cross-sectional area of 5.90 ✕ 10−6 m2. Carry out steps (a)...

An iron wire has a cross-sectional area of 5.90 ✕ 10−6 m2. Carry out steps (a) through (e) to compute the drift speed of the conduction electrons in the wire. (a) How many kilograms are there in 1 mole of iron? _____________ kg/mol (b) Starting with the density of iron and the result of part (a), compute the molar density of iron (the number of moles of iron per cubic meter). ___________mol/m3 (c) Calculate the number density of iron atoms...