Like all equilibrium constants, the value of K_w depends on temperature. At body temperature (37 °C), K_w = 2.4×10^–14. What are the [H₃O⁺] and pH of pure water at body temperature?

The value of K_w increases with increasing temperature. Is the autoionization of water endothermic or exothermic?

Determine whether or not the mixing of each pair of solutions results in a buffer. e. 105.0 mL of 0.15 M CH₃NH₂; 95.0 mL of 0.10 M HCl

Calculate the pH of each acid solution. Explain how the resulting pH values demonstrate that the pH of an acid solution should carry as many digits to the right of the decimal place as the number of significant figures in the concentration of the solution. [H₃O⁺] = 0.044 M [H₃O⁺] = 0.045 M [H₃O⁺] = 0.046 M

Determine the concentration of H₃O⁺ to the correct number of significant figures in a solution with each pH. Describe how these calculations show the relationship between the number of digits to the right of the decimal place in pH and the number of significant figures in concentration. pH = 2.50 pH = 2.51 pH = 2.52

For each strong acid solution, determine [H₃O⁺], [OH^–], and pH. a. 0.25 M HCl

For each strong acid solution, determine [H₃O⁺], [OH^–], and pH. b. 0.015 M HNO₃

For each strong acid solution, determine [H₃O⁺], [OH^–], and pH. c. a solution that is 0.052 M in HBr and 0.020 M in HNO₃

For each strong acid solution, determine [H₃O⁺], [OH^–], and pH. d. a solution that is 0.655% HNO₃ by mass (assume a density of 1.01 g/mL for the solution)

What mass of HI must be present in 0.250 L of solution to obtain a solution with each pH value?

a. pH = 1.25 b. pH = 1.75 c. pH = 2.85

What mass of HClO₄ must be present in 0.500 L of solution to obtain a solution with each pH value? a. pH = 2.50 b. pH = 1.50 c. pH = 0.50

What is the pH of a solution in which 224 mL of HCl(g), measured at 27.2 °C and 1.02 atm, is dissolved in 1.5 L of aqueous solution?

Determine the [H₃O⁺] and pH of a 0.100 M solution of benzoic acid.

Determine the [H₃O⁺] and pH of a 0.200 M solution of formic acid.

Determine the pH of an HNO₂ solution of each concentration. In which cases can you not make the simplifying assumption that x is small? a. 0.500 M b. 0.100 M c. 0.0100 M

Determine the pH of an HF solution of each concentration. In which cases can you not make the simplifying assumption that x is small? (K_a for HF is 6.8×10^–4.) a. 0.250 M b. 0.0500 M c. 0.0250 M

A 0.185 M solution of a weak acid (HA) has a pH of 2.95. Calculate the acid ionization constant (K_a) for the acid.

Determine the percent ionization of a 0.125 M HCN solution.

Determine the percent ionization of a 0.225 M solution of benzoic acid.

Calculate the percent ionization of a formic acid solution having the given concentration. a. 1.00 M

Calculate the percent ionization of a formic acid solution having the given concentration. b. 0.500 M

Calculate the percent ionization of a formic acid solution having the given concentration. c. 0.100 M

Calculate the percent ionization of a formic acid solution having the given concentration. d. 0.0500 M

A 0.148 M solution of a monoprotic acid has a percent ionization of 1.55%. Determine the acid ionization constant (K_a) for the acid.

Find the pH of each mixture of acids. a. 0.115 M in HBr and 0.125 M in HCHO₂

Find the pH of each mixture of acids. b. 0.150 M in HNO₂ and 0.085 M in HNO₃ c. 0.185 M in HCHO₂ and 0.225 M in HC₂H₃O₂ d. 0.050 M in acetic acid and 0.050 M in hydrocyanic acid