Answer the following questions, showing calculations and equations where appropriate:
1. Steponaitis, Blackman, and Neff (American Antiquity 61:555-572, 1996) use the following correction for bulk elemental concentrations measured in shell- tempered pottery: e' = (1000000*e)/(1000000-2.5Ca), where e' = corrected elemental concentration, e = originally measured elemental concentration, Ca = concentration of calcium, and all measurements are in parts per million (ppm). Explain how this correction works. Hint: Assume that the shell temper is pure calcium carbonate, CaCO3.

Solution Preview

e' = 1000000*e/(1000000 - 2.5Ca)
divide by 10^6 (=1000000) in numerator and denominator, we get,
=> e' = e/[1 - {2.5*Ca*10^(-6)}]
=> e' = e/[1 - {(100/40)*Ca*10^(-6)}]
Now look at this expression: (100/40)*Ca*10^(-6)
because,
Ca = concentration in ppm
therefore,
Ca*10^(-6) = parts of calcium per unit of the material, i.e., ...

Solution Summary

The solution answers the question with explanation and a step-by-step equation process.

Answer the following questions, showing calculations and equations where appropriate:
1. Your analytical technique directly and accurately measures the concentration of iron-54 in your samples. How would you calculate the total iron concentration from these concentrations? What if you wanted to know the iron-oxide concentrati

Answer the following questions, showing calculations and equations where appropriate:
1. You have a radiocarbon sample analyzed and find out that the sample has 60% of the modern level of radiocarbon. Calculate the radiocarbon age of the sample using (a) an assumed 5730-year half-life and (b) a 5568-year half-life.

A 3.00 L flask initially contains 1.50 mol of gas A and 0.450 mol of gas B. Gas A decomposes according to:
3A <-> 2B + C
DeltaH = +90kJ mol^-1
The equilibrium concentration of gas C is 0.100 mol/L.
What is the equilibrium concentration of gas A?
What is the equilibrium concentration of gas B?
What is the equilibrium co

Hey there. I am having trouble with this question.
Calculate the molar concentration of OH- ions in a 0.550 M solution of hypobromite ion (BrO-; Kb=4.0 x 10^-6). What is the pH of this solution?
Could you please show the work. And no power points please.
Thanks in advance!

Please help with the following problem. Provide step by step calculations in this answer.
A 25.00 mL sample containing Cu2+ gave an instrument signal of 23.6 units (corrected for a blank). When exactly 0.500 mL of 0.0287 M Cu(NO3)2 was added to this solution, the signal increased to 37.9 units. Calculate the molar concentrat

In each of the following pairs, indicate which has the higher concentration of Cl- ion:
0.10 M CaCl2 or 0.15 M KCl solution,
100ml of 0.10 M KCL SOLUTION OR 400 ML OF 0.080M LiCl solution,
0.050 M HCL solution or 0.020 M CdCl2 solution
Please provide a detailed explanation.

1) What is the pH of a solution prepared by adding 7.21 mL of 2.14 M NaOH to 1.00 g of hypochlorous acid (HOCl, FW - 52.46, pKa = 7.53), 1.00 g sodium hypochlorite (NaOCl, FW - 74.44) and diluting to 100.0 mL.
2) What mass of solid citric acid (g) and how many milliliters of 0.500 M NaOH are needed to produce 100.0 mL of a bu

2) Two substances Q and R each have the elemental composition C = 60% h=13.3% 0=26.7% by mass
0.60 grams of each substance occupied a volume of 0.336 liters at 137 Celcius and standard pressure
a) Calculate the empirical formula and the relative molecular mass of Q and R.
B) What is the molecular formula

1. A water sample has a pH of 8.21 and a total calcium concentration of 143 ppm.
(a) What are the molar concentrations of CO3 2- and HCO3- ?
(b) What is the total alkalinity of the water?