Calculate the pH of a 0.50 M solution of sodium benzoate (NaC₆H₅COO) given that the K_a of benzoic acid (C₆H₅COOH) is 6.50 x 10^-5.

The initial concentrations of Na+ and Cl− in the reaction below are each 0.0843 M. If the initial concentration of NaCl is 0 M and the equilibrium constant is Kc=8.21 under certain conditions, what is the equilibrium concentration of Na+?

NaCl(aq)⇌Na+(aq)+Cl−(aq)

12) Calculate the change in pH when 3.00 mL of 0.100 M HCl(aq) is added to 100.0 mL of a buffer solution that is 0.100 M in NH3(aq) and 0.100 M in NH4Cl(aq).

delta pH=?

Calculate the change in pH when 3.00 mL of 0.100 M NaOH(aq) is added to the original buffer solution.

delta pH=?

Draw a sketch for the Hydrogen (discrete) spectrum, labeling the lines according to their respective quantum transitions. Also point out in which direction the wavelength increases.

1. Retention time (tR) is a measure of how long a compound is retained on a stationaryphase in column in column chromatography. In TLC, Rf was a measure of how long thecompound was retained on the stationary phase. What is the relationship between tR and Rf?

2. What would be the order of elution if one separated the pigments of spinach on columnchromatography?

3. What if any would you have to change in terms of the mobile phase if you wanted toactually perform the column chromatography in order to separate the pigments of spinachcompare to the one used for the TLC Experiment? Explain.

4. Why is it important to keep the solvent level above the stationary phase? What wouldhappen if one lets the solvent get much lower than the alumina stationary phase?

40.0 mL of 0.10 M HA(aq) was titrated against 0.10 M NaOH(aq). HA (aq) is a weak acid with K_aof 6.3 x 10^-6.

            (a)        Calculate the initial pH of the 0.10 M HA (i.e. before adding NaOH).

            (b)        Calculate the pH at the equivalence point.

1) Calculate scattering particles off of a single crystal of nickel. The Ni lattice spacing is 2.15 x 10-10 m. Compute the angle for the first order diffraction feature assuming you bombard the system with:

a. X-ray photons of energy 18.0 keV.

b. Electrons with kinetic energy 18.0 keV.

c. Neutrons with kinetic energy 18.0 keV.

d. What do you conclude from your results above?

calculate pH from 75 ml of 0.1M CH3COOH and 25 ml of 0.1 M Ca(OH)2

Consider the following reaction:
2NO(g)+O2(g)→2NO2(g)
Estimate ΔG∘ for this reaction at each of the following temperatures and predict whether or not the reaction will be spontaneous. (Assume that ΔH∘ and ΔS∘ do not change too much within the give temperature range.)

A)298 K

B)735 K

C)855 K

50 mL of 0.060 M K₂CrO₄ is mixed with 50 mL of 0.080 M AgNO₃. Calculate the following:

a. The solubility of Ag₂CrO₄ (K_sp = 1.9 X 10^-12) in the solution in moles per liter.

b. The concentrations of the following ions Ag⁺, CrO₄^-2, K⁺, and NO₃^-.

A little stuck, could you please show working out?

Which of the following processes represents an oxidation reaction?

Which one of the following processes represents a reduction reaction?

50lbs of gas with the specific gavity of .88(treat as real gas) is in a tank at p=1384 psig and at T=320F what is volume of the tank in ft^3        This question is in oilfield units

Using a table of standard electrode potentials, decide which of the following statements is completely true.

A. Cu2+ can oxidize H2, and Fe can reduce Mn2+ .

B. Ni2+ can oxidize Cu2+, and Fe2+ can reduce H+ .

C. Fe2+ can oxidize H2, and Fe2+ can reduce Au3+ .

D. Br2 can oxidize Ni, and H2 can reduce Mn2+ .

E. H + can oxidize Fe, and Ni can reduce Br2.

Answer: E.. but why? can you explain why A-D are incorrect and why E is right. I know it has something to do with how they are positioned on the standard reduction potential list, but I dont understand the concept, which I will need to know for my exam. thank you!

Under the topic of aqueous chemical equilibria, outline the quantitative treatment of a single acid in solution. Indicate in your answer, where a mass balance expression is utilised.