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Classify each of the following as a Lewis acid or a Lewis base. H– : [h-] Br– : [br] Fe3+ : [fe] NH3 : [nh3] BH3 : [bh3]

A buffer with highest capacity can be achieved when pH is equal to the pKa of its acid component. A buffer solution is prepared by adding 0.050 M NaOH to [V1] mL of 0.010 M nitrous acid, HNO2. At which volume of sodium hydroxide added will the buffer subsequently achieve its highest buffer capacity? Input your answer to 1 decimal place.

Consider the crystal field splitting pattern for octahedral complexes to answer the following questions. A. How many electrons are unpaired in a d6 high-spin complex? [A] B. How many electrons are unpaired in a d4 low-spin complex? [B]

An unknown metal M that has Ksp of MS in water is [Ksp] x 10−22 and Kf of M(OH)42− is [Kf] x 1014. Calculate the molar solubility of MS in 2.0 M NaOH. Multiply your answer by 104 and express the final answer to 2 decimal places.  

The de Broglie equation predicts that the wavelength (in m) of a proton moving at 1000. m/s is ________. (mass of a proton = 1.673 × 10–24 g)

Calculate the pH of a solution containing [c]M pyridine, C5H5N. (Kb = 1.7×10-9) Express your answer to two decimal places.

 PbCl2 has a Ksp of 1.1×10−5. Solutions of lead (II) nitrate and aluminum chloride are mixed, forming a solution containing 0.020 M Pb(NO3)2 and 0.010 M AlCl3. What can be said of this solution?

The following anions can be separated by precipitation as lead salts: OH-, I–, CrO42–, AsO43- . If Pb2+ is added to a solution containing the four anions (each anion at a concentration of 0.10 M) in what order will they precipitate?   First, [I] Second, [II] Third, [III] Fourth, [IV]   Compound Ksp PbCrO4= 1.8 x 10–14 Pb3(AsO4)2= 4.1 x 10–36 Pb(OH)2= 2.8 x 10–16 PbI2= 8.7 x 10–9

Which one(s) of the following combinations (I to VI) that after being mixed can possibly create a buffer solution? Choose an answer containing all those combinations  I. HIO3 and KOH II. NH3 and HBr III. HNO2 and NaNO2 IV. H2SO4 and Na2SO4 (assume H2SO4 deprotonates completely into SO42-) V. HNO3 and NH4NO3 VI. CH3NH2 and CH3NH3Cl 

Calculate the wavelength (in nm) of the blue light emitted by a mercury lamp with a frequency of 6.88 × 1014 Hz.