We noted in an earlier practice exercise that at 25 celsius the decomposition position of N2O5(g) into NO2(g) follows first order kinetics with k= 3.4 x 10^-5 s^-1. How long will it take for a sample originally containing 2.0 atm of N2O5 to reach a partial pressure of 380 torr?

At 25

Q: Why does a prism separate light into different colors ?

A voltaic cell consists of an Mn/Mn²⁺ half-cell and a Pb/Pb²⁺ half-cell. Calculate [Pb²⁺] when [Mn²⁺] is 2.7 M and E_cell = 0.35 V.

How would you explain to a concerned consumer what food irradiation is, and its benefits? What negative effects, if any, are there regarding food irradiation? What stance do you take on food irradiation?

Explain in your own words what the overall catalytic efficiency really compares and what it tells us about our enzyme

You collect a sample of hydrogen gas in an inverted buret by displacement of water at 23 degrees C. The buret could not be submerged deep enough in the water level in the water bath. The volume of gas in the buret was determined to be 32.60 mL.

a. If the current atmospheric pressure was 29.45" of Hg, what is the pressure of dry hydrogen in the buret? Show your work.

b. How many moles of hydrogen are in this sample? Show your work.

You are given a sample of several compounds to separate by paper chromatography. You draw a pencil line exactly 1.0 cm from the bottom of the paper, and place a spot of sample on it. You dry the sample, then develop it in a solvent.

When the chromatogram is taken out of the solvent, the paper is wet up to 9.1 cm from the bottom of the sheet. The compound you are interested in shows up as a spot 7.1 cm from the bottom of the paper.

Calculate the following:

In the same time, how far did the solvent move?

What is the Rf factor for the compund?

1. The pH of 0.070 M aniline (C₆H₅NH₂) is 8.73. What are its K_b and pK_b?

2. What mass of potassium hydrogen sulfate is required to make 309 mL of a solution with a pH of 2.27? (The K_a of HSO₄^? = 0.012.)

3.What is the pK_a of iodic acid if the iodate ion concentration in a 0.058-M solution of HIO₃ is 0.045 M?

--I got the answer 1.457 but it is marking it as wrong and im not sure why.

Doing homework and got stumped on these 3 problems. Please help me.

What would be the speed of the following particles if they had the same wavelength as a photon of orange light (λ = 625.0 nm)?

1.Proton (mass = 1.673 × 10–24 g)

2.Neutron (mass = 1.675 × 10–24 g)

3.Electron (mass = 9.109 × 10–28 g)

4.Alpha particle (mass = 6.645 × 10–24 g)

For each of the following side chain interactions in a protein, give an example of two amono acids that interact that way and draw a structure that illustrates the interaction.

a. Hydrophobic interaction, b. Metal ion coordination, c. Covalent bond (in the side chain), d. Hydrogen bonding, e. Salt bridge

In Acid - Base equilibria  problems, how do you know what are the major species. I mean what do " major species " mean exactly?

  19. The pH of a solution prepared by mixing 50.0 mL of 0.125 M NaOH and 40.0 mL of

0.125 M HNO₃ is ____

   [A] 13.29 [B] 8.11 [C] 11.00 [D] 12.14 [E] 7.00

20. The pH of a solution prepared by mixing 50.0 mL of 0.125 M KOH and 50.0 mL of 0.125 M HCl is ______

[A] 1.34 [B] 5.78 [C]1.90 [D] 1.14 [E] 7.0

21. Consider the following table for K_sp values

Which will have the least solubility in the given solvent?

[A] CdCO₃ [B] Cd(OH)₂ [C] CdF₂ [D] AgI [E] ZnCO₃

  22. What is the molar solubility of magnesium oxalate ( MgC₂O₄) in water? The solubility-

   product constant for MgC₂O₄ is 8.6 x 10^-5 at 25 °C.

[A] 4.07 [B] 1.7 x10^-4 [C] 1.3 x10^-2 [D] 4.3 x10^-5 [E] 9.3 x10^-3

The enthalpy change for the following reaction is -748 kJ. Using bond energies, estimate the C≡O bond energy in CO(g). 2CO(g) + 2NO(g)2CO2(g) + N2(g)

The inversion of compound B is experimentally determined to follow the rate law: d[B]/dt = -k[B]^a[H⁺]^b.
At 25 °C and a constant pH of 3.00, the reaction proceeds with a constant half-life of 40.0 min. At this same temperature, but at a constant pH of 1.00, the half-life is constant at 4.00 min. What are the exponents (orders) a and b in the above rate law?