Temperature affects the dissociation of water into hydronium and hydroxide ions. Given the molalities of hydronium ions at 5 °C, 25 °C, and 45 °C, calculate the values of K_w (in 3 s.f.) at 5 °C and at 45 °C (at 5 °C,  [H₃O⁺] = 4.32×10⁻⁸ mol/kg of water, at 25 °C, [H₃O⁺] = 1.00×10⁻⁷ mol/kg of water, and at 45 °C, [H₃O⁺] = 1.97×10⁻⁷ mol/kg of water).

At 50.0°C, K_w is 5.5 x 10^-14. Determine [OH^-] in pure water at this temperature.

What are the [OH^-], [H₃O⁺], pH, and pOH for 0.30 M KOH?

What is the hydroxide concentration, [OH^-], of a KOH solution with a pH of 11.3?

Determine the concentration of a solution that was prepared by dissolving 18.0 g of arsenic acid (H₃AsO₄) in water to make a 750 mL solution. Express the concentration in terms of molarity and normality.

A stink bomb is composed of an aqueous solution of ammonium hydrosulfide. It is used as a malodorant and a riot control agent. What are the chemical reactions that lead to the compound/s responsible for the strong unpleasant smell of stink bombs?

Complete and balance the following neutralization reactions, make sure to include phases:

1. Ba(OH)₂ (aq) + H₂SO₄ (aq) →

2. KOH (aq) + HClO₄ (aq) →

A volcanic eruption can be demonstrated using vinegar and baking soda. Foam and bubble overflow simulates the eruption. How are the foam and bubble formed when baking soda solution is mixed with vinegar? Which substance can be used as an antacid?

In alcoholic ketoacidosis, the level of acidic molecules is elevated. These molecules form in the liver from the breakdown of fats and proteins for energy due to low sugar levels or lack of nutrients. Explain how this condition affects the pH of the blood.

Which of the following describes a good buffer solution?

The pH in our stomach is regulated by a bicarbonate buffer system. The constituents of the buffer system are H₂CO₃ and HCO₃^–. If carbonic acid (H₂CO₃) has a pK_a of 6.37, provide the Henderson-Hasselbalch equation for this bicarbonate buffer.

The volume of an HCl waste is 10000 mL. It has a pH of 2.0. A small bottle contains 1.0 g of Ca(OH)₂. Show the neutralization reaction between hydrochloric acid and calcium hydroxide. Determine how many milliliters (in 1 s.f.) of the HCl waste can be neutralized by two small bottles of Ca(OH)₂.

The river Banyupahit originates from the world's largest acidic lake in the crater of Kawah Ijen volcano. A sample of the river water has been taken and observed to have a pH of 3.3, far below the normal pH range of 6-8 for stream water. Determine how many grams of Ca(OH)₂ can neutralize a 50 mL river water sample if the acid in the river is sulfuric acid. 

Ca(OH)₂(s) + H₂SO₄(aq) → CaSO₄(s) + H₂O(l)

Consider the following balanced equation:

2 HCl(aq) + Ba(OH)₂ → BaCl₂ + 2 H₂O(l)

Calculate the volume of a 0.280 M HCl solution needed to completely neutralize 30.0 mL of 0.325 M Ba(OH)₂.

A. 70.0 mL

B. 17.4 mL

C. 69.6 mL

D. 1.36 mL

E. 5.46 mL