Chem exam 2

Which of the following statements regarding physiological pH and the
carbonic acid–bicarbonate buffer system (shown below) is NOT correct?

CO2(aq) + H2O( ) ⇌ H2CO3(aq) ⇌ H+(aq) + HCO3−(aq)

• The carbonic acid–bicarbonate buffer system regulates the
  concentration of CO2 dissolved in blood.

• When the amount of CO2 dissolved in blood decreases, the pH
  decreases

• When CO2 is produced by respiration, the system shifts to the right

• When acid is added, the system shifts left, which prevents a large pH
  decrease

• When base is added, the system shifts right, which prevents a large pH
  increase

Which of the following compounds, when added to a saturated solution of
Pb(OH)2, will increase its solubility?

• PbCl2

• NaOH

• NaCl

• HNO3

• NH3

From the list below, select the best indicator that could be used to detect
the equivalence point for the titration of 1.0 M NaOH with 1.0 M HCl.

• Methyl orange

• Bromophenol Blue

• Methyl Red

• Bromothymol Blue

• Phenolphthalein

Consider the reaction: Ce(IO3)3(s) ⇌ Ce3+(aq) + 3IO3−(aq) Ksp = 1.9 x 10−10

For a solution that is 2.86 x 10−3 M Ce(NO3)2 and 5.71 x 10−3 M KIO3, what is
the value of Q, and will a precipitate form?

• Q = 5.32 x 10−10 no precipitate

• Q = 1.63 x 10−5 no precipitate

• Q = 5.32 x 10−10 precipitate will form

• Q = 1.63 x 10−5 precipitate will form

• It is impossible to tell

Which of these titrations has an equivalence point with pH > 7?

• NH4Cl titrated with NaOH

• HCl titrated with KOH

• NaCH3COO titrated with HBr

• NaNO2 titrated with HNO3

• HClO4 titrated with LiOH

Lead pipes were used at one time for delivering drinking water. What is
the concentration of lead in water if it comes from lead(II) hydroxide (Ksp
= 2.8 x 10–16) dissolving from the surface of the pipes?

• 4.1 x 10–6 M

• 1.6 x 10–8 M

• 6.5 x 10–6 M

• 5.1 x 10–6 M

• 8.3 x 10–9 M

What is the pH at the equivalence point for a titration of 40.0 mL of 2.23
M propionic acid (Ka = 1.3 x 10–5) with 1.25 M KOH ?

• 11.88

• 7.00

• 4.75

• 2.67

• 9.39

At what point in the following titration curve for a weak acid being titrated
with a strong base is the pH equal to the pKa of the acid?

• 0.0mL

• 5.0 mL

• 9.0 mL

• 10.0 mL

• 18.0 mL

Which of the following is NOT a strong acid or base?

• HClO4

• HClO3

• Mg(OH)2

  
  

• RbOH

• NaOH

HXY2 is a strong acid. The balanced equation for its ionization in
water is:

• HXY2 + H2O ⇌ HX+ + 2Y− + H2O

• HXY2 + H2O  H3O+ + XY2−

• HXY2 + OH−  XY2− + H2O

• H+ + XY2 ⇌ H2O + 2XY

• none of the above