Table of Contents
- 1 Why can h2s in presence of dilute HCl precipitate out only second group radicals but not fourth group radicals?
- 2 Why dilute HCl is not used in the preparation of h2s?
- 3 Why H2S gas is passed?
- 4 Why is H2SO4 used instead of HCl explain the principle of salt analysis?
- 5 Why HCl is not used in electrolysis of water?
- 6 Why is dilute h2so4 preferred over dilute HCl during anions?
- 7 Which pair of ions are precipitated upon passing h2sgas in dilute HCl?
- 8 Why do we pass H2S gas in acidic medium in Group 2?
Why can h2s in presence of dilute HCl precipitate out only second group radicals but not fourth group radicals?
It is due to. Dissociation of H2S is suppressed in presence of HCl due to common ion effect. This decreases the S2- ion concentration and hence only group 2 radicals are precipitated as they have low solubility products.
What is the role of HCl in the analysis of Group 2 basic radicals?
HCl is used for the analysis of group II cations. The group II metals have low solubility product and thus easily precipitates on the exposure toH2S. HCl do not oxidize the metal ions and are used as the group reagent.
Why dilute HCl is not used in the preparation of h2s?
Answer: Explanation: Nitric acid not used in the laboratory preparation of hydrogen. sulphuric acid and dilute hydrochloric acid do not oxidise hydrogen into water hence preferred for the preparation of hydrogen gas.
Why is dilute HCl added in the test for Group 2 cations?
The cations of group II are precipitated as their sulphides when H2S gas is passed through their solution acidified with HCl. Due to common ion effect of H+ ions, the degree of dissociation of H2S is suppressed, so the concentration of sulphide ions decreases. …
Why H2S gas is passed?
H2S gas is passed in presence of HCl, in qualitative analysis of cation of second group, therefore, due to common ion effect, lower concentration of sulphide ions is obtained which is sufficient for the precipitation of second group cations in form of their sulphides due to lower value of their solubility product (Ksp) …
Why HCl is added before H2S gas?
Answer: Why HCl is added before H2S gas during qualitative analysis of second group radicals. The concentration of sulphide ions is suppressed by HCl due to common ion effect. The already present H+ ions suppress the dissociation of H2S by moving the reaction in the backward reaction.
Why is H2SO4 used instead of HCl explain the principle of salt analysis?
When HCl dissolve in water, it will dissociate into one mole of H+ ion and Cl- ions. Whereas, the H2SO4 dissociate into two mole of 2H+ and SO4^2- . Hence,the number of H+ ions produced by H2SO4 is higher and easily replace with other compounds. It is possible for these acids to form more than one type of salt.
Why HCl is used in salt analysis?
H2S dissociates less than HCl and we get less conc. of sulphide to precipitate. Thus, We add HCl during salt analysis required for less conc. of sulphides.
Why HCl is not used in electrolysis of water?
Because HCl is a concentrated acid and if we try to use it for acidifying water and put some of it in water, then it will burn us as steams will be released suddenly which will not give us a chance for escaping them. Thus, it is advised not to use Hcl for this pupose. We can use other acids like ethanoic acid,etc.
Why does alcohol dissolve in concentrated hydrochloric acid?
Ethanol reacts with concentrated HCl with formation of ethyl chloride. The first step in the reaction is the protonation of hydroxyl group and second step is the elimination of water followed by the attack of halide ion as a nucleophile to form substitution product.
Why is dilute h2so4 preferred over dilute HCl during anions?
H2SO4 is preferred while testing acid radicals over dil. HCl? Ans. So the actual gas cannot be identified whereas with H2SO4, no such problem arises.
Which group gives precipitate when H2S gas is passed in basic solution of substance?
Group III (Al3+, Cr3+, Fe3+, Zn2+, Ni2+, Co2+, Mn2+) cations produce slightly soluble sulfides (Ksp values more than 10-20) so they can be precipitated by relatively high amounts of sulfide ion; this can be achieved by adding a basic solution of H2S.
Which pair of ions are precipitated upon passing h2sgas in dilute HCl?
The pairs of ions where both the ions are precipitated upon passing H2Sgas in presence of dilute HCl, are Cu2+,Pb2+and Hg2+,Bi2+. The ions Cu2+,Pb2+,Hg2+and Bi2+belong to group IIA. Thy precipitate as sulphides. The group reagent is hydrogen sulphide in presence of HCl.
What happens when H2S is passed in the presence of Dil HCl?
We’ve put together a list of 8 money apps to get you on the path towards a bright financial future. When H2S is passed in presence of dil.HCl, the dissociation of H2S is weak due to common ion effect.
Why do we pass H2S gas in acidic medium in Group 2?
Find out everything you need to know about it here. Then, why do we pass h2s gas in acidic medium in Group 2? H2S is passed through the solution in an acidic medium to precipitate the sulphides of group II cations but in an alkaline medium to precipitate the sulphides of group IV cations because: A .
Why does H2S precipitate less than HCl?
So as to reduce conc. of sulphides ions,common ion effect of H+ is required.H2S dissociates less than HCl and we get less conc. of sulphide to precipitate. HCl is a strong acid. It is fully ionised and have high concentration of H+ ion.