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Solid NH4SH is introduced into an evacuated flask at 24oC. The following reaction takes place

What is the pH of a buffer solution that contains 0.40 mol hydrocyanic acid (HCN) and 0.30 mol potassium cyanide (KCN) in water sufficient to yield 1.0 L of solution?  Hint: The Ka of HCN is 4.9 x 10-10.

Which of the following statements regarding reactions rates is true?

The diagrams here represent solutions at various stages in the titration of a weak base B (such as NH3) with HCl. Which image best represents the solution in the at the inital stage before the addition of HCl ? 

Given the following reduction potentials:                                                               Eored Cr3+(aq)  + 3e- →  Cr(s)                      –0.74 V Fe3+(aq)  +  e- →  Fe2+(aq)                 +0.77 V Calculate the equilibrium constant, K, for the following reaction.               Cr(s)    + 3    Fe3+(aq)   →   Cr3+(aq) + 3 Fe2+(aq) Hint:  Remember that a voltaic cell runs on a spontaneous redox reaction.   Hint: Make sure to determine the total moles of electrons transferred for the cell.  

Consider the following equilibrium reaction: CH4 (g)  +  2 H2S (g)   ⇌   CS2 (g)   +  4 H2 (g)           Kc= 4.28  Which of the following statements best describes the composition of the reaction mixture at equilibrium?  

Consider the following balanced redox reaction: 3 SO2 (g)  +  2 HNO3 (aq)  +  2 H2O (l)  →   3 H2SO4 (aq)  +  2 NO (g)      How many total electrons are transfered in this reaction? 

Consider the following equilibrium reaction: CH4 (g)  +  2 H2S (g)   ⇌   CS2 (g)   +  4 H2 (g)           Kc= 4.28 x 10−4 Which of the following statements best describes the composition of the reaction mixture at equilibrium?

Consider the following pH curve plots for four different titrations:   Which plot shows the expected pH curve when nitric acid, HNO3, is titrated by potassium hydroxide, KOH?

Copper metal, Cu (s), is produced by running a current through a solution of Cu2+ in an electrolytic cell. How many grams of copper metal can be deposited from Cu²⁺(aq) when a current of 1.50 A is run for 75 min? Hint:  F = 96,500 C/mol e− Hint:  1 A = 1 C/s