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An aqueous solution is found to have an H+ concentration of 2.0 x 10-4 M.  What is the concentration of OH- in this solution?

The following 4 Essay questions require you to submit your work.  All work must be in your own handwriting.  The use of electronic devices, including writing tablets is not allowed.  No work= No credit.  Work must be neat and legible. If I cannot read it, you will not receive credit for it.    

The net ionic equation for the reaction, Cu (s) + 2 HNO3 (aq) –>  H2(g)  + Cu(NO3)2 (aq)  

The precipitate for the following precipitation reaction is ___.   LiBr (aq)  +  AgNO3 (aq)  —> ?

Airbags rapidly produce nitrogen gas through reactions like this one: 2 NaN3 (s) –> Na (s) + 3 N2 (g)   In this reaction, what volume of nitrogen gas can be produced by the reaction of 12.5 g of NaN3, if the temperature is 365 K and the pressure is 1.200 atmospheres?  The formula mass of NaN3 = 65.00 g/mol.   The answer must have the correct significant figures ( 1 pt) and unit ( 1 point) . Circle your final answer.  All work must be shown for credit. No work=no credit. All work must in your own hand-writing.    

Consider the following equation.  Cu (s) + 2 HBr (aq) –>  CuBr2 (aq)  +  H2 (g) A 100. mL solution of 0.025 M HBr that completely reacts with copper metal will produce ___ moles of hydrogen gas.

What is the pH of a 7.8 x 10-2 M KOH solution?   The answer must have the correct significant figures ( 1 pt) and unit ( 1 point) . Circle your final answer.  All work must be shown for credit. No work=no credit. All work must in your own hand-writing.  

A 3.0 kg sample of pond water contains 3.6 mg of a pollutant.  What is the concentration of this pollutant in ppm?

A 50.0 mL sample of H2SO4 is neutralized with NaOH solution having a concentration of 2.00 M.  If 35.5 mL of NaOH are required to complete the neutralization, what is the concentration of the sulfuric acid solution? The answer must have the correct significant figures ( 1 pt) and unit ( 1 point) . Circle your final answer.  All work must be shown for credit. No work=no credit. All work must in your own hand-writing.  

What is the correct electronic geometry and molecular geometry around the central nitrogen in NO2-?  (Hint:  you may need to draw the molecule.)