Passage Potassium permanganate (KMnO 4 ) is a highly reactive inorganic salt that appears as granular dark purple crystals, nearly black in color. Due to its useful chemical properties and the fact that its reactions typically do not produce compounds that are toxic, KMnO 4 is employed in a variety of applications, including use as a topical skin disinfectant, an antifungal agent, a fire starter, and a disinfectant for drinking water.KMnO 4 is widely used as an alternative water treatment agent both to disinfect drinking water and to remove undesirable dissolved iron and sulfur compounds. The crystals are highly soluble in water and form bright pink aqueous solutions that provide a visual indication of the presence of KMnO 4 treatment residual. As a drinking water disinfectant, a KMnO 4 concentration of 1 mg/L is recommended unless higher levels of contamination are indicated by the absence of a pink residual.Industrial production of potassium permanganate is accomplished in two steps. In step 1, manganese(IV) oxide (MnO 2 ) is heated with potassium hydroxide in the presence of oxygen to produce potassium manganate (K 2 MnO 4 ), as outlined in Reaction 1.2 MnO 2 + 4 KOH + O 2 → 2 K 2 MnO 4 + 2 H 2 OReaction 1In step 2, the potassium manganate is then converted into potassium permanganate electrochemically according to Reaction 2.2 K 2 MnO 4 + 2 H 2 O → 2 KMnO 4 + 2 KOH + H 2 Reaction 2 -What volume of H₂ gas will be generated in Reaction 2 described in the passage if 10.00 L of a 5.00 M solution of K₂MnO₄ react at standard temperature and pressure (STP)?

Question

Quizplus · Accepted Answer

11ecba2d_11d9_e5d6_a3bf_f151b339fb13_MD0008_00 The molarity of a solution is the number of moles of solute present in 1 L of solution. The number of moles of reactant can be related to the number of moles of product formed in a reaction by the stoichiometric mole ratios obtained from the balanced reaction equation. If the reaction product is a gas, the volume the gas will occupy depends on both temperature and pressure. The volume of a gas is often stated under conditions of standard temperature and pressure (STP), which are defined as 0°C (273.15 K) and 1 atm pressure. Under STP, 1 mole of gas occupies a volume of 22.4 L. For Reaction 2, the number of moles of K₂MnO₄ present in 10.0 L of solution can be calculated: (10.0 L solution) × (5.00 mol/L) = 50.0 moles K₂MnO₄ Reaction 2 is balanced and shows that 1 mole of H₂ is produced for every 2 moles of K₂MnO₄ that react. Applying this ratio, the number of moles of H₂ produced can be determined: (50.0 moles K₂MnO₄) × (1 mol H₂) / (2 mol K₂MnO₄) = 25.0 mol H₂ At STP, the molar volume occupied by the H₂ gas produced in the reaction is given by: (25.0 mol H₂) × (22.4 L/mol) = 560 L H₂ (Choice A) If the number of moles of H₂ is divided rather than multiplied by 22.4 L/mol, a result of 1.12 L is obtained. (Choice B) If the reacting solution volume is divided instead of multiplied by the K₂MnO₄ solution molarity, a result of 22.4 L is obtained. (Choice D) If a 1:1 (H₂ : K₂MnO₄) mole ratio is used rather than a 1:2 mole ratio, a value of 1120 L results. Educational objective: Given the volume of a solution, its molarity, and a balanced reaction, mole ratios can be determined that relate the moles of a reactant present in the solution to the moles of a product produced from the solution. For gaseous products, the number of moles produced can be related to the molar volume using 22.4 L/mol, the volume 1 mole of gas occupies at STP.

Passage Potassium Permanganate (KMnO4) Is a Highly Reactive Inorganic Salt That

Passage Potassium Permanganate (KMnO₄) Is a Highly Reactive Inorganic Salt That