SAT Subject Test Chemistry,10 edition

(Marvins-Underground-K-12) #1

NH 3 + H 2 O → NH 4 + + OH−


C.


NO 2 − + H 2 O → HNO 2 + OH−


D.


4 . 0.067


At  the equivalence point,

Plugging    into    the formula,

5 . 10.2


First,  add enough  HCl to  neutralize  the solution.   Since   both    the acid    and the base    are 1   M,  10
mL of HCl will neutralize 10 mL of NaOH. This produces 20 mL of 0.5 M NaCl solution.

Next,   calculate   how much    more    HCl must    be  added   to  produce a   [H+]    of  1   ×    10 −2. Let x   be  the
amount of HCl to be added. The total volume of the solution will be (20 + x) mL. Since this is
now a dilution problem, the amount of HCl to be added can be found by using the formula:

When    this    equation    is  solved, x   is  found   to  have    the value   of  0.2.    The final   volume  is  20.2    mL, so
10.2 mL of HCl was added to the original NaOH solution.

6 . (H 2 O, OH−) and (NH 4 +, NH 3 )


NH 4 + is   the conjugate   acid    of  the weak    base,   NH 3 ;  OH− is  the conjugate   base    of  the weak    acid,
H 2 O. The reaction in question is:
Free download pdf