Potassium Dichromate | d Block Chemistry | Jee Mains, Advance, BITSAT, NEET & AIIMS
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- เผยแพร่เมื่อ 13 ต.ค. 2024
- Hello Guys, Phobia of Potassium Dichromate??? Now, No need to worry about this. You are watching right lecture. Learn super concept and tricks about K2Cr2O7 for Jee Mains/Advance/NEET/BITSAT and AIIMS with our mentor MKA Sir (M.Tech, IIT Kharagpur).
Potassium Dichromate, K2Cr2O7
• Preparation of Potassium Dichromate
It is prepared from the ore called chromate or ferrochrome or chrome iron, FeO.Cr2O3. The various steps involved are
(a) Preparation of sodium chromate
4FeO.Cr2O3 + O2 → Fe2O3 + 4Cr2O3
4Na2CO3 + 2Cr2O3 + 3O2 → 4Na2CrO4 + 4CO2
(b) Conversion of sodium chromate into sodium dichromate.
2Na2CrO4 + H2SO4 → Na2Cr2O7 + Na2SO4 + H2O
(c) Conversion of sodium dichromate into potassium dichromate.
Na2Cr2O7 + 2KCl → K2Cr2O7 + 2NaCl
• Properties of Potassium Dichromate
It forms orange red crystals. It is moderately soluble in cold water but freely soluble in hot water.
1. Action of heat
When heated, it decomposed to its chromate
4K2Cr2O7 → 4K2CrO4 + 2Cr2O3 + 3O2
2. Action of alkalis
With alkalis it is converted into chromate which on acidifying gives back dichromate.
K2Cr2O7 + 2KOH → 2K2CrO4 + H2O
2K2Cr2O7 + H2SO4 → K2Cr2O7 + K2SO4 + H2O
In dichromate solution the Cr2O72- ions are in equilibrium with Cr2O72- ions at pH = 4.
Cr2O72- + H2O → 2CrO42- + 2Hl
orange red yellow
3. Action of conc. H2SO4 solution
• In cold conditions
K2Cr2O7 + 2H2SO4 ---→ 2CrO3 + 2KHSO4 + H2O
• In hot conditions
2K2Cr2O7 + 8H2SO4 ---→ 2K2SO4 + 2Cr2(SO4)3 + 8H2O + 3O2
4. Oxidising properties
It is a powerful oxidising agent. In the presence of dil. H2SO4 it furnishes 3 atoms of available oxygen.
K2Cr2O7 + 4H2SO4 → K2SO4 + Cr2(SO4)3 + 4H2O + 3O
Some of the oxidizing properties of K2Cr2O7 are
1. It liberates I2 from KI
K2Cr2O7 + 7H2SO4 + 6Kl → 4K2SO4 + Cr2(SO4)3 + 3l2 + 7H2O
2. It oxidises ferrous salts to ferric salts
K2Cr2O7 + 7H2SO4 + 6FeSO4 → K2SO4 + Cr2(SO4)3 + 3Fe2(SO4)3 + 2H2O
3. It oxidises S-2 to S
K2Cr2O7 + 4H2SO4 + 3H2S → K2SO4 + Cr2(SO4)3 + 7H2O + 3S
4. It oxidises nitrites to nitrates
K2Cr2O7 + 4H2SO4 + 3NaNO2 → K2SO4 + Cr2(SO4)3 + 3NaNO3 + 4H2O
5. It oxidises SO2 to SO42-
K2Cr2O7 + H2SO4 + 3SO2 → K2SO4 + Cr2(SO4)3 + 3H2O
6. It oxidises ethyl alcohol to acetaldehyde and acetic acid.
5. Chromyl Chloride Test
When heated with conc. HCl or with a chloride in the presence of sulphuric acid, reddish brown vapours of chromyl chloride are obtained.
K2Cr2O7 + 4KCl + 6H2SO4 → 2CrO2Cl2 + 6KHSO4 + 3H2O
Thus reaction is used in the detection of chloride ions in qualitative analysis.
We Hope you will enjoy the lecture.
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IITian explains
Guys, You must remember these colors in this content..
Cr2O7 (2-) Red Orange
CrO4 (2-) Yellow
CrO3 Red Crystals
CrO5 Deep blue
Cr(3+) Green
CrO2Cl2 Reddish Brown Gas
Thanks
MKA Sir
IITian explains
thank u sir...
IITian explains
Shukriya Sir
Thanks sir
30 mins ke baad nhi smjh aa rhi h
IITian explains sir awesom videos
CHEMISTRY CAN NEVER BE MONOTONOUS UNTIL THE FUEL OF YOUR INDEPTH KNOWLEDGE IS IGNITED TO THE STUDENTS.
HATS OFF TO YOU AGAIN FROM CORE OF MY HEART.....
Explanation is your strength.. Keep explaining like this.Good work.
NO MATTER WHAT THE TOPIC IS, THE INDEPTH CONCEPT YOU DELIVER MAKES YOU THE EXCEPTIONAL AND ABOVE THE REST. THE CHEMISTRY- CONQUERING TEACHER YOU ARE. IMMENSE INDEPTH KNOWLEDGE YOU POSSESS.
INCREDIBLE, WHAT A CHEMISTRY ADEPT!!!!!!!+++🙋♂️🙋♂️🙋♂️🙋♂️🙋♂️
31:05 'God of chemistry' for a reason
BRO have you seen the reference what is mentioned by sir? Still I have doubt on it. I thought -2 & +6 are the oxidation states how +4 will come? Please explain.
@@hariprasad3390 should i explain now ?
Sir honestly speaking u r the best teacher ur lectures are full of knowledge
Never imagined this topic could become so easy. Great work sir
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You are the best professor I have ever heard and want to hear again and again..
Thank you so much sir!❤❤
I really don't understand how can someone teach so good! Hats off to you sir!!!
Sir...
Thank u so much for giving lecture on this topic and u ware right..have phobia of this agent
And I really learnt a lot from you!!! 🌸 :)
Guriji You always worked sincerely even before 3 yrs .im your plus student .aapka lectures se bhut kuch seekhne ko milte thank you guruji ❤️
Kya badhiya padhate hain aap sir...Lajavaab☺️
I am extremely flattered that how you explain the concept so wonderfully
Hats off to you sir
Ek no. Video sir
Allah apko hamesha khush rakhe,
😊😇😇
Sir according to fajans rule , Polarizing power is inversely proportional to size of cation . Since size of Na + is smaller so its polarizing power will be more . Due to more polarising power its polarisation will be high and so covalent character will be high too and covalent character is inversely proportional to solubility in H2O . so solubility of Na2Cr2O7 should be less than K2Cr2O7
For larger anions sol. Is deciding by lattice energy
Cr2o7(2-) ka colour orange hota hain na?at 42:26 you said yellow Hain.?
Sir at one or other day you will be the best educator in TH-cam sir
sir you add an another level of charm to the topic... really well explained...
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sir parson advance ka paper hai aur mai pyqs dekhraha tha d block ke aadhe se zyada to issi lecture me cover hogye .....Thanks a lot (aim top 1000)
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Pehli baar samjh aaya yeh topic mjh....
Thanks so much sir...
Yeh topic clear ktwane ke liye.....✌ ✌
30:38 sir So2 to +2 ke increment ke sath So3 bhi to bna skta hai. pls explain
Very helpful video sir..!!!!
but sir in S2O3(2-) how is the sulpher atom on the right side is showing 0 oxidation state..???? i have not understood...
Sir I can't thank you enough, I have gained so much knowledge and confidence from your videos that I don't fear exams anymore. Thank you for your efforts.
Bohot Accha explain kiya hai sirr.... Thanku very much.. 😇😇😇
Sir your passion for the subject is incredible. Great indepth knowledge...thank you so much sir for your amazing efforts ❤️
dichromate and chromate ion both are d3s hybridised.. refer mka sir's coordination lecture on tetrahedral complex
Seriously no one can compete u in explanation of this topic
Tq so much sir....I was very frusted for this topic and then I show your video lacture...tq tq so much sir...
Sir, you are a living gem!!! Thank you sir
kaash sare teachers aise pdate to aaj india kaha hota!!
Best inorganic teacher in the world 👌
I am aspiring iitian...and in the top fiitjee batch ...we all had problem in in organic chemistry and u saved us all...
Plzz continue the great work sir ..it's our only hope in inorganic
Perfect but one doubt
Time 23.37
Dichromate react with h2so4
At high temperatures
There are
Cr +6 convert In to cr+3 reduction
There are oxidation which one???
Its oxygen??
Awesome.. GRt job..!!! Hats off to u..!!!!
U r just wonderful..!!! IIT guy rocks..!!!! 😊😊
HII Akshita
@@ashokgodara4756 Why
Chut de riya ka
Di re ka
Sab tharki h comments mein..😂😂😂
Jones reagent converts one degree alcohol to carboxylic acids not aldehydes .
Thanks For Amazing session 👑👑👑
One doubt.
14:11 the colour of Cr+3 Is violet as given in ncert...
What should we consider?
Sr good morning . I pass out in 1994 msc in CHEMISTRY sp inorganic. Abhi mai cement industry me manager hu process ka. Mere chhota beta kota me taiyari kr rha hai IIT Ka. Abhi 97 percentile bana hai. आपका लेक्चर इतना जोरदार है कि मुझे फिर से पड़ने की आदत हो गई। और अपने बच्चे को पोस्ट करता हु इम्पोर्टेड पॉइंट को। थैंक्स सर जी
aap na to sir inorganic ka phobia hi mita diya thank you sir
37:20 CRO3 will form , red crystal not cro5
A direct question from this lecture came in JEE ADC 2020. Structure of CrO5 wad to be deduced from the color given P-2 eqn-3
When I take yr lectures
I don't control my smile
You are amazing sir
Your tricks every thing
3 se 4 saal purani vid hai yeh
..but abhi bhi koi aur vid usko takkar nhi de sakti ...
Sir, in the preparation of the potassium dichromate from sodium dichromate with potassium chloride ,
Why chloride is not changing to chlorine even though it is in the presence of such a strong oxidising agent .
42:30 pe kuch hua kya 😂 Guruji Dedication 101%
I think I am the only one who noticed this... lol 😆🤣😂😹
Bahut bahut pasand aaya sir thankyou thankyou thankyou thankyou pls make this type of video--mission jeee
So conceptual approach
Sir, your explanation are really nice & very much depth.
Keep uploading videos on inorganic chemistry & help students to love chemistry from the bottom of their heart😊
Ur way is too different frm others.. So simple nd sleek way of xplaining, but too effective sirr😇
43:15
Sir in k2cr2o7 , is the hybridization of Cr sp3 or sd3??....i read somewhere that it's sd3...plz confirm
it is d3s
Sir plz make video on metal carbonyl related concept
i agree...
Right...
Its too hard to cram all these equations..
Its really hard..
Thanks for this wonderful explaination
Tomorrow is my exam..
This lecture is reallly helpfull..
Thank you so much
so how did your exam went??
Sir 30:15 jo reaction hai uska nfactor 6 hoga na??? Doubt pls clear iodide wala
you are the best inorganic teacher
Love u sir....... faadu.....Jhakkasss....Jabardast...... coolllll....Thankyou sir.
are bhai bhai bhai...
U r amazing .... After seeing this video...Now this topic is clearly clear to me without a single doubt...thanks a lot sir
this video help to clear concept at aiims level
Ur explanation is awesome
Sir this one was nice. Now please upload on potassium permanganate topic👍
Techno world
u r exactly right
Techno world very very nice
Beauty✨ with brain.... Nice 😊 combination sir
you gay bro?
Hypo (S2O32-)to sulphate (SO4 2-) n factor = 4 .
your voice seems to be similar to dusyant Kumar sir
Nice explaination 10XX.........
Sardna tutorials ki tarah act Kar rahe hai
Thank u very much you are a very nice teacher and lecture is awesome
Sir I got 97 percentile in jee mains with ur video only Nd now Preparing for jee adv with ur video only. .. thanks a lot
At pH=4 , they're are at equilibrium
Nice sir please upload more videos on Co ordination compounds
Sir, resonance ke liye sare bonds ek plane me hone chahiye. To Cr2O7(2-) mein resonance kaise hua
Why we use sulphuric acid? can we use perchloric acid?
app k mja har chezzz smj ata h thnxxx sirrr app hmra liya itna mhnt krta ha
Sir, at 30:15, wouldn't the n-factor of Iodide(I-) be 1? Because n-factor is the total no. of electrons lost or gained by 1 mole of the reactant....and here, 2 moles of I- are losing 2 electrons...so, 1 mole would lose only 1.....so, shouldn't the n-factor of Iodide be 1?
But nevertheless, I loved the trick.....would help me a lot, sir...thank you.....and amazing hard work undertaken by you in the lab, just to figure out a trick to make us understand the concepts better.....
Direct one question in advance 2020 fom this lecture 🤩
Sir O(-1) is having oxidation no (-2)? in S2O3(2-) then S should have+6?? Please ans I am confused
SIR can u chek the n fator of x- in the reaction x- ---> x2..... it is one not 2 and u have repeated that several times i think so u should check it out....
Sir, within a very less time you had given his lot of knowledge thank you very much sir.
chemistry in every day life me compunds ki struture kaise yaad kare.
sir nucleophilic substitution reactions aur unke types samjha dijeye....
Wow sir
Nice explanations😀😀😀
I can say i have studied for EXACTLY 45 minutes
Hybridisation in Cr2O7(-2) is d3s/sp3???
D3S
Plzz upload a video on n-factor .
And what is the n - factor of Al2Cl6 and why is the n-factor of Mohr's salt =1 , .
Plzz upload on n-factor of challenging questions.
Thank you very much MKA SIR❤❤❤❤
sir aap kaha hai??
please aur sare video upload kijiye.
aapke lecture bahut jyada help karte hai.
thanks sir.
you are best guruji love youuuu so much ty so much aise sessions se ioc yaad hojata hai
Sir s2o3 ka mostly redox ke sums me hum 2.5 leke karte hai na
JAI HOO! sir ji u r doing a great job
i'm completely in love with your inorganic videos
KAMAL HAI GURU JIII MAAJ AA GYAAAA
Uh hv explained everything very clearly but our teacher explained the first step tht is the conversion of chromite ore to sodium chromate by using sodium hydroxide nd involved only one reaction so... Im little bit confused.... Sir.... Plz reply in comment plzzzzzzzzzzzz
Otherwise ha teaching sense is very awssssmmmm thnnkwww sirrr
MSc BHU entarence exam ke liye sahi rahe sakta hai
Sir plz keep making these type of videos and you are the best
sir please give a short trick to find no.of isomers in coordination compounds faster without drawing the structures(optical+geometrical)
Sir can plz share any trick for calculating geometric isomers
Very good teaching sir
Thanks a lot sir
Really excellent tricks sir 👌👌👌👌
Aditya Pathak jee sir good
very nice plz make a video on physical properties of d and f block elements
very clear concept. I love this. thank u sir give us more videos to make organic chemistry easier. it's very helpful for me.
THANK YOU SIR....
Great content
Sir you are helping a lot of students.
Also the intro music is very pleasing.
Wah sir kya samjhaya apne ...really...maja...agaya...
If k2Cr2O7 oxidises KI to I2 .. can it oxidise I2 to HIO; similarly can it oxidise HIO to HIO2 and so on
sir crystal clear teachings hats off after a long time seeings such a piece off works .it will be thank full of uu to make a video lecture on equilibrium
Sir plz upload the video lecture on potassium permanganate before board exam
Is there any option of 2 likes...
What a trick sir...
M hamesha ratne me lga rhta tha isko but ab conceptual learning 😉
Binod .. finally I got you
you are just cool !!
your strength is your analysis and explanation
you are taking it to different level sir
thank you so much