A student carrying out out a Spectrophotmetric dtermination of copper in Brass lab experiment was in a hurry to finish. The student decided to omit the filtering step of the procedure because the brass solution did not appear very cloudy. It turned out that there was tin in the sample.

a) Did the omission of the filtering step cause a high or low result? Briefly explain.

b) Also during the filtering process some of the brass solution is absorbed by the filter paper. Would this cause a high or low result for percent copper? Briefly explain.

1-The lines observed in H-lamp are parts of Balmer Series. All these lines are due to a transition from various higher n value to a common n. What is this common lower n value for all these lines?

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Question 2

The bright violet line of Hg lamp has a wavelength of 435.8 nm. What is the energy of the photon associated with this emission line?

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Question 3

Given: In Atomic Spectra lab, a student obtained his best-fit line equation to be y = 0.29 x + 46.8 when he plotted his Vernier reading on the y-axis and wavelength in nm on the x-axis.

Question: If the Vernier reading for a line is 229.5, what is the predicted wavelength of this line in nm? (Keep 4 sig figs with one decimal place.)

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Question 4

The only electron in a hydrogen atom moved from n=2 to n=6. What is the wavelength of photon (in nm) being associated with this transition? Use whole numbers of nm without any decimal places, such as "415", "1125".

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Question 5

Which of the following transitions of the only electron in hydrogen atom will emit longest wavelength photon?

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Question 6

A student obtained the Rydberg constant to be 2.12*10-18 J. What is the % error of the measurement? Answer as percentage and keep one decimal place.

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Question 7

Which of the following orbitals of O has the lowest energy?choose all the right answer

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Question 8

A 100-mL sample of Pb initially has a concentration of 14.3 ppm. If this sample was diluted to 300 mL, what is the new concentration in ppm? Keep one decimal place for your answer.

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Question 9

Which of the following is directly proportional to the concentration of a solution sample?

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Question 10

When measuring the transmittance of the Fe standard solution, what is used as blank?

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Question 11

When intensity of light changes due to sample absorption, which of the following change accordingly?

Part C

Add the following reactions together:

ClO(g)+O3(g)ClO2(g)+O(g)??ClO2(g)+O2(g)ClO(g)+O2(g)

Identify which species are intermediates, which are catalysts, and which are only reagents or products.

Drag each item to the appropriate bin.

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A particular reactant decomposes with a half-life of 131 s when its initial concentration is 0.361 M. The same reactant decomposes with a half-life of 233 s when its initial concentration is 0.203 M. What is the value and unit of the rate constant for this reaction?

what the technical barriers for hydrogen production using solar?

For each of the reactions, calculate the mass (in grams) of the product formed when 15.30 g of the underlined reactant completely reacts. Assume that there is more than enough of the other reactant

1) 2K(s)+Cl2(g)−−−−−→2KCl(s)

Express your answer using four significant figures

2) 2K(s)+Br2(l)−−−−−→2KBr(s)

Express your answer using four significant figures

3) 4Cr(s)+3O2(g)−−−−−→2Cr2O3(s)

Express your answer using four significant figures

4) 2Sr(s)−−−−+O2(g)→2SrO(s)

Express your answer using four significant figures

How do I determine polarity from a lewis structure? Please show me step by step. Thank you

The area of Pluto is 44,828 mi2 . If a mole of 0.50 mm cubic particles were evenly spread over Pluto, how deep, in meters, would the particles be?

A battery charger used to recharge the NiMH (nickel metal-hydride) batteries used in a digital camera can deliver as much as 0.35 A of current to each battery. If it takes 145 minutes to recharge one battery, how much Ni(OH)2 (in grams) is oxidized to NiO(OH)?

H2O(l) + e? + NiO(OH)(s) ? OH?(aq) + Ni(OH)2(s)

Synthesis of Lidocaine. Write out a scheme for each of the reactions with the mass of each reagent calculate the theoretical yield for each reaction. Use the theoretical yield of the first reaction as the starting material mass of the second reaction.

How much 5M KOH must be added to a 1.0L of 0.1M glycine at pH 9.0 to bring its pH to exactly 10.0? When 99% of the glycine is in its protonated form, what is the numerical relation between the pH of the solution and the pKA of the amino group?

Titration with an indicator is a common technique that chemists use when counting moles.

a ) Would this technique be useful for determining the pH of a water sample from a lake or stream?

b) Can this technique determine if a lake or stream is affected by acid rain?

Draw extraction schemes that would separate:-

(a) naproxen and cortisone.

(b) ibuprofen from caffeine;

(c) acetaminophen and ibuprofen;

K_p has the value 1.00x10^-5 for the equilibrium

CO2(g) + H2(g) <--> CO(g) + H2O(g)

at 25^oC and ΔS_o is -41.9 J/K (ΔH_o and ΔS_o do not change much with temperature). One mole of CO, 2 moles of H₂, and 3 moles of CO₂ are introduced into a 5-liter flask at 25^oC. Calculate

(a) ΔG_o at 25^oC,

(b) the equilibrium pressure,

(c) the moles of each species present at equilibrium,

(d) K_p at 100 0C. The mixture obeys the ideal equation of state.