Why hcl should not be used for potassium permanganate titration

\( \newcommand\) • • • • • • • • • • • • • • • • • • • • • • • Learning Objectives Goals: • Understand that parts of an acid-base titration • be able to determine the K aor K bfrom pH data associated with the titration of a weak acid or base • be able to determine the molar mass of a solid monoprotic acid from titration data • be able to calculate K a1and K a2for a polyprotic acid By the end of this lab, students should be able to: • design, develop and performacid base titrations . Prior knowledge: • • Stoichiometry of Acid-Base Titrations in quantitative analysis (s Concurrent Reading & AdditionalResources • pH and pOH ( • pH of Weak Acids and Bases ( • pH of salts ( • buffers ( Safety • Emergency Preparedness • E ye protection is mandatory in this lab, and you should not wear shorts or open toed shoes. The following image shows the damage 4 M sodium hydroxide can cause. By following proper procedures and using proper PPE (Personal Protective Equipment)the risk to damage can be reduced to near zero.There are two primary factors that determine the extent of injury due toexposure to corrosive chemicals like NaOH, the concentration of the chemical and the time of contact (exposure to the chemical). For this reason we do not perform titrations with concentrated acids and bases, but dilute ones. If you ever have an acid or base spill you need to immediately inform your instructor, who will clean it up or instruct you on what to do. If you spill it on your body you should imme...

Table of Contents • • • • • • • • Why KMnO4 is a secondary standard? KMnO4 is not used as primary standard because it is difficult to obtain the pure state of KMnO4 as it is not free from MnO2. Also, the colour is so intense that it acts as its own indicator. Why does potassium permanganate need to be standardized right before a titration? Some chemical reactions are very sensitive to the exact amount of reagents used otherwise the reaction will not work properly. Once the exact concentration has been determined, the solution is said to be standardized and you can then add exact amounts of the KMnO4 to a chemical reaction. Why can’t potassium permanganate be used as a primary standard? Potassium permanganate is one of the oxidising agents in chemistry. Potassium permanganate is not used as primary standard because is not able to release in \[\] in the reaction. Potassium permanganate is always in the stable form. What is the best standard to be used in the standardization of potassium permanganate? As potassium permanganate is not a primary standard it can be standardized by using sodium oxalate or oxalic acid. The former is preferred over oxalic acid as available in a higher standard of purity (99.95%). Is HCl a secondary standard? Hydrochloric acid (HCl) solutions as a secondary standard A HCl solution is used as it can be prepared accurately and is quite stable. Because of this stability it is called a secondary standard. Even more accurate and stable standards are call...

https://chem.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fchem.libretexts.org%2FBookshelves%2FInorganic_Chemistry%2FSupplemental_Modules_and_Websites_(Inorganic_Chemistry)%2FDescriptive_Chemistry%2FElements_Organized_by_Block%2F3_d-Block_Elements%2FGroup_07%253A_Transition_Metals%2FChemistry_of_Manganese%2FChemistry_of_Manganese Expand/collapse global hierarchy • Home • Bookshelves • Inorganic Chemistry • Supplemental Modules and Websites (Inorganic Chemistry) • Descriptive Chemistry • Elements Organized by Block • d-Block Elements • Group 7: Transition Metals • Chemistry of Manganese • Chemistry of Manganese Expand/collapse global location \( \newcommand\). The reaction of hexaaquamanganese(II) ions with hydroxide ions Hydroxide ions (from, say, sodium hydroxide solution) remove hydrogen ions from the water ligands attached to the manganese ion. Once a hydrogen ion has been removed from two of the water molecules, you are left with a complex with no charge - a neutral complex. This is insoluble in water and a precipitate is formed. \[[Mn(H_2O)_6]^ + 2OH^- \rightarrow [Mn(H_2O)_4(OH)_2] + 2H2O\] In the test-tube, the color changes are: I have shown the original solution as very pale pink (the palest I can produce!), but in fact it is virtually colorless. The pale brown precipitate is oxidized to darker brown manganese(III) oxide in contact with oxygen from the air. The reaction of hexaaquamanganese(II) ions with ammonia solution Ammonia can act as both a base an...