Sulfuric acid is used because it is stable towards oxidation; whereas, for example, hydrochloric acid would be oxidized to chlorine by permanganate.
Why do we need to add H2SO4 when we dissolve FeSO4?
Ferrous ions of Mohr’s salt undergo hydrolysis in aqueous solution. To prevent the hydrolysis, Conc. H2SO4 needs to be added to the Mohr’s salt crystals during the preparation of its standard solution. Another reason is also to prevent the oxidation of Fe2+ ions of Mohr’s salt to Fe3+ ions.
What happens when FeSO4 reacts with H2SO4?
That means FeSO4, KMnO4, and H2SO4 react to produce the Iron(III) sulfate, Manganese sulfate, potassium sulfate as well as water.
Why is a mixture of sulphuric acid and phosphoric acid used in the determination of Fe?
Usually H2SO4 and H3PO4 are added the sulfuric is the main source of H3O+ the phosphoric acid is added to complex Fe+3. By lowering the concentration of ferric ion the change in redox potential is increased making the endpoint easier to see or measure electronically. What is the pH of a 0.15 M phosphoric acid solution?
Why is sulphuric acid used in titration?
Sulphuric acid is added to prevent hydrolysis and to provide surplus H+ ions in the solution to keep reaction proceeding and also sulphuric acid is stable towards oxidation.
What is the purpose of adding phosphoric acid in the Fe titration?
In the redox titration of iron(III) with permanganate or dichromate, we use phosphoric(V) acid to “mask” the color of iron(III) because it interferes with the end point color change.
Is FeSO4 soluble in H2SO4?
By raising temperature and the concentration of HCl, more FeSO4∙7H2O can be dissolved in this system. However, with the addition of H2SO4, the solubility of FeSO4∙7H2O is found to decrease due to common-ion effect.
Why it is necessary to add few drops of concentrated H2SO4 in the preparation of FAS solution?
The reason why you add sulfuric acid before adding water is that the oxidation of the ferrous ion by dissolved oxygen in water is fast at neutral to high pH. By dissolving FAS in water with no acid added and watching the solution turn a cloudy orange, indicating the formation of ferric Ions.
Why sulphuric acid is added into conical flask before titration?
Sulphuric acid is added to prevent hydrolysis and to provide surplus H+ ions in the solution to keep reaction proceeding and also sulphuric acid is stable towards oxidation. From the above reaction it is evident that 8 moles of H+ ions is required per mole of MnO4- so sulphuric acid provides the required hydrogen ion.
What type of reaction is H2SO4 Fe → h2 FeSO4?
Type of Chemical Reaction: For this reaction we have a single displacement reaction.
What happens when freshly prepared ferrous sulphate is added to the mixture of conc HNO3 and conc H2SO4?
Ans- When FeSO4 is added to the well cooled mixture of dilute HNO3 and conc. H2SO4, it give brown ring of nitrous ferrous sulphate.
What happens when nitric acid react with FeSO4?
FeSO4 + 4 HNO3 → Fe(NO3)3 + H2SO4 + NO2 + H2O – Balanced equation | Chemical Equations online!
Why is phosphoric acid used instead of sulfuric acid?
Since H2SO4 is an oxidizing agent, it oxidizes HI (produced in the reaction to I2). As a result, the reaction between alcohol and HI to produce alkyl iodide cannot occur. Therefore, sulphuric acid is not used during the reaction of alcohols with KI. Instead, a non-oxidizing acid such as H3PO4 is used.
Why is sulfuric acid stronger than phosphoric acid?
Sulphuric acid is stronger than phosphoric acid. Reasons: The oxidation number of sulphur in sulphuric acid is +6 whereas that of phosphorous in phosphoric acid is +5. The number of O—H bonds in sulphuric acid is 2 but that in phosphoric acid is 3.
Why was sulfuric acid used but not phosphoric acid for this titration?
Sulfuric acid is a strong acid, whereas phosphoric acid is a weak acid. In turn, the strength of an acid can determine the way in which a titration occurs.
Why do we use H2SO4 instead of HNO3 or HCl?
HCl isn’t suitable, as will be oxidised to chlorine gas by the permanganate whilst HNO3 is an oxidising agent itself and would interfere with the reaction. H2SO4 (as long as it’s dilute) doesn’t have this problem, so is the preferred medium for such oxidations (especially for titrations).
Why is H2SO4 used for acidification of KMNo4?
Answer. HNO3 is also a powerful oxidizing agent along with KMnO4 so it also plays its role in oxidation which causes a decline in the value of KMNo4 used. As dilute sulfuric acid is ideal for redox titration because it is neither an oxidizing agent and nor a reducing agent.
