Suppose you dissolved benzoic acid, C6H5COOH, in water to make a 0.15 M solution. Ka for benzoic acid = 6.3 x 10-5 at 25°C. What is:
the concentration of benzoic acid?
the concentration of hydronium ion?
the concentration of benzoate anion?
the pH of the solution?
Hydroxylamine, NH2OH is a weak base with a Kb = 6.6 x 10-9. What is the pH of a 0.36 M solution of hydroxylamine in water at 25°C? Fill out the ICE box below to help.
Hydroxylamine, NH2OH is a weak base with a Kb = 6.6 x 10-9. What is the pH of a 0.36 M solution of
hydroxylamine in water at 25°C? Fill out the ICE box below to help.
Reaction: NH2OH + H2O ↔ NH3OH+ + OHI
x
C
E
pH:
Determine the pH of a 0.36M HOCN solution. (Ka = 3.5 x 10-4) Fill out the ICE box below to help.
Reaction: HOCN + H2O ↔ OCN- + H3O+
I
x
C
E
pH:
Cyanic acid HOCN has a Ka = 3.5 x 10-4
a. What is the Kb for the cyanate ion OCN-
?
b. Compare the strength of cyanic acid to that of HCN (Ka = 4.0 x 10-10). Then compare the
strengths of their conjugates.
For each of the following salts, predict whether an aqueous solution would be acidic, basic, or neutral.
sodium nitrate NaNO3
ammonium iodide NH4I
sodium bicarbonate NaHCO3
ammonium chloride NH4Cl
lithium hypochlorite LiOCl
potassium acetate KCH3CO2
Write the reaction of each of these substances with water:
Write the reaction of each of these substances with water:
H2S (weak acid)
NH3 (weak base)
HCOO-
(weak base)
Weak Acids and Bases
- Four equations showing the reaction of an acid in water is given below.
(I) HNO3(aq) + H2O(l) ↔ H3O+(aq) + NO3
(aq) Ka = very large
(II) H2CO3(aq) + H2O(l) ↔ H3O+(aq) + HCO3
(aq) Ka = 4.2 x 10-7
(III) NH4
+(aq) + H2O(l) ↔ H3O+(aq) + NH3(aq) Ka = 5.6 x 10-10
(IV) HCN(aq) + H2O(l) ↔ H3O+(aq) + CN-
(aq) Ka = 4.0 x 10-10
Using the equation above, determine…. (you may use the equations once, more than once, or not at all)
a. The strongest acid
b. The acid that produces the lowest concentration of hydronium ions per mole of acid
c. The diprotic acid
d. The acid with the weakest conjugate base
e. The acid with the strongest conjugate base
50.0 mL of 0.20M Ba(OH)2 is added to 75.0mL of 0.250M HNO3. Determine the following information: Excess reactant Moles of excess reactant pH of final solution
50.0 mL of 0.20M Ba(OH)2 is added to 75.0mL of 0.250M HNO3. Determine the following information:
Excess reactant Moles of excess reactant pH of final solution
Write the neutralization reaction for Ba(OH)2 and HNO3 Ba(OH)2 + 2HNO3 → Ba(NO3)2 + 2H2O
Write the neutralization reaction for Ba(OH)2 and HNO3
Ba(OH)2 + 2HNO3 → Ba(NO3)2 + 2H2O
50.0 mL of 0.20M NaOH is added to 450.0mL of 0.050M HNO3. Determine the following information: Excess reactant, Moles of excess reactant, pH of final solution
50.0 mL of 0.20M NaOH is added to 450.0mL of 0.050M HNO3. Determine the following information:
Excess reactant, Moles of excess reactant, pH of final solution
