0.1040 g of a solid sample containing copper was dissolved by acid and transferred to a 250.00 mL volumetric flask and volume was made up with distilled water. The solution was then diluted by a factor of 20. The final solution was analyzed by atomic absorption spectrophotometry and the concentration was found be 3.109 ppm, What is the weight percentage of copper in the original solid sample? Keep four significant figures in your final answer. Do not try to include the "%" in your answer. e.g. if your final answer is 10.01%, only write 10.01 in the box.

A solution was prepared from an amount n = (0.500 ± 0.005) mol dissolved in a volume V = (250.0 ± 0.5) cm3. What is the absolute uncertainty in the concentration in units of mol dm-3?

A 10.00 mL of natural water sample containing Ni2+ was pipetted into a volumetric flask and diluted to 50.00 mL with pure water. In the second 10.00 mL of natural water sample transferred into a volumetric flask, exactly 4.00 mL of a Ni2+ solution with a concentration of 5.99 mg/L was added and then diluted to 50.00 mL with pure water. The measured absorbance is A1= 0.436 and A2 = 0.663. What is the Ni2+ concentration in unit of mg/L in the natural water sample?

Q4 (a) Analyze the importance of dropping mercury electrode on polarography.  (b) (i) Calculate the molarity of MgSO4 in a solution containing 1.5 g ofMgSO4 in a volume of 250 mL?(ii) Calculate the weight of MgSO4 in grams which is present in 100mL of 0.076 M MgSO4?(c) Evaluate the key differences between paper chromatography and gaschromatography

A second spectrophotometric method for the quantitative analysis of Pb2+ in blood yields an Ssamp of 0.712 for a 5.00 mL sample of blood. After spiking the blood sample with 5.00 μL of a 1560 ppb Pb2+ external standard, an Sspike of 1.546 is measured. What is the concentration of Pb2+ in the original sample of blood?

The pharmacist attempts to weigh 80mg of sodium carbonate on a balance having a sensitivity requirement of 4mg. Calculate the maximum potential error in terms of percentage.

Example: You wish to prepare a calibration curve for the spectrophotometric determination of permanganate. You have a stock 0.100 M solution of KMnO4 and a series of 100 mL volumetric flasks. What volumes of the stock solution will you have to pipet into the flasks to prepare standards of 1.00 x10³, 2.00 x10-³, 5.00 x103, and 10.0 x103 M KMnO4 solutions? Solution: for 1.00 x10-³ 0.1 (M1X V1)conc. = (M2 X V2) dil mmol |x V1 = 1.0 × 10-3 -) x 100 (ml) mL mmoly mL V₁= 1.0 mL stock solution. Take home work for the 2.00 x10-3, 5.00 x10³, and 10.0 x10-³ M.

A student prepared four standard solutions of (NH4)2Fe(SO4)2 and measured their absorbance at 505 nm.  She created a calibration plot with the best-fit line of y = 9372 x + 0.0539.  She measured the absorbance of her diluted unknown sample solution as (4.69x10^-1) nm.  If she prepared her diluted sample solution by diluting 10.00 mL of the original solution to a total volume of 50.00 mL with deionized water, what is the concentration of Fe2+ in her original solution?  Answer in units of M. Note: Your answer is assumed to be reduced to the highest power possible.

professor Scimemi has accepted you as a Master’s student and you are involved in a project that studies the cellular basis of neuropsychiatric diseases. For your electrophysiology recordings you have to make a recording solution containing (in mM): 119 NaCl, 2.5 KCl, 2.5 CaCl2, 1 MgCl2, 26.2 NaHCO3, 1 NaH2PO4, 22 glucose. You need 800 ml of it. How much KCl do you need to weigh out? Hint: we only care about KCl here. (MW KCl is 74.55 g/mol

Quantitative Analysis by External Standard Method Calcium in a juice sample is determined by atomic absorption spectrophotometry. A stock solution of calcium is prepared by dissolving 1.834 g of CaCl, 2H20 in water and diluting to 1000.0 mL. A substock calcium solution was prepared by transferring 10.00 mL of the stock to a 100.00 mL volumetric flask and diluting to the mark. Three standard solutions of calcium were prepared by transferring 2.500 mL. 5.00 mL and 10.00 mL of substock to 50.00 mL volumetric flasks and diluting to the mark. The sample is prepared by transferring 1.000 mL of fruit juice from the original bottle to a 25.00 mL flask and diluting to the mark. Strontium chloride is added to all solutions before dilution to avoid phosphate interference. Instrumental response of the standards is measured against the blank, and the following readings are recorded: 9.10, 18.6 and 37.0. The sampie reading is 28.1. Using the multipoint method, find the concentration of calcium in…