. A 225-g sample of aluminum was heated to 125.5 °C, then place into 500.0 g of water at 22.5 °C. Calculate the final temperature of the mixture. The specific heat of aluminum is 0.900 J/g°C and the specific heat of water is shown as 4.184 J/g°C; assume no heat loss
to the surroundings.
2. A solution of vinegar is 0.763 M acetic acid, HC2H3O2. The density of the vinegar is 1.004 g/mL. What is the molal concentration (m) of acetic acid?
3. How would you prepare 72.5 g of an aqueous solution that is 2.50% (by mass)N potassium iodide, KI?
4. Calculate the moles of H2O that can be obtained from 15.0 mL of 0.250 M HCl according to the following equation: 2 KMnO4(aq) + 16 HCl(aq) → 2 MnCl2(aq) + 5 Cl2 + 8 H2O(l) + 2 KCl(aq)
5. When the following cations and anions react, if the product is insoluble in water, write the net ionic equation for the precipitate reaction.
(a) Ag+ and Cl- (b) Ba2+ and SO4
2- (c) Na+ and Cl-
, (d) Zn2+ and NO3
–
6. Use the Arrhenius and Brønsted-Lowry theories to define acid and base
7. Calculate the concentration of hydronium ion, hydroxide ion, and pH at 25oC in (a) 0.15 M HNO3, (b) 0.010 M Ca(OH)2.
8. In the following equations, label each species as an acid or a base. Show the conjugate acid-base pairs:
(a) HCO3- (aq) + HF(aq) H2CO3(aq) + F- (aq) (b) HCO3- (aq) + OH-
(aq) CO32- (aq) + H2O(l)9. Predict whether each of the following salts will form an acidic, basic, or neutral
solution
10. Indicate the conjugate base of the following Brønsted-Lowry acids:
(a) H2SO3 (b) HC2H3O2 (c) H2AsO4 – (d) NH4 +
11. Lactic acid (HC3H5O3) has one acidic hydrogen. A 0.10 M solution of lactic acid has a pH of 2.44. Calculate the Ka of lactic acid.
12. The acid-dissociation constant for hypochlorous acid (HClO) is 3.0 × 10-8. Calculate the concentrations of H3O+, ClO-, and HClO at equilibrium if the initial concentration of HClO is 0.0075 M.
13. Calculate the pH of a buffer that is 0.12 M in lactic acid and 0.11 M in sodium lactate. (Ka = 1.4 × 10–4)
14. A buffer consisting of lactic acid and sodium lactate has a pH = of 4.30. Given that the concentration of lactic acid is 0.12 M, and Ka = 1.4 × 10–4, calculate the concentration of sodium lactate.