Loha Jang Kyun Khata Hai?
Jab loha hawa ki oxygen aur paani (nami) se ek saath milta hai, toh dheere-dheere ek nayi bhoori-laal cheez ban jaata hai: jang. Yeh loha ka “bimaar” hona nahi, ek chemical badlaav hai 🔩
📖 Kahani: “Golu ki Cycle ko Kya Ho Gaya?”
Barsaat ki chhuttiyon ke baad Golu apni purani cycle nikaalne balcony mein gaya. Cycle poore mahine baahar, gate ke paas khadi rahi thi, kai baar baarish mein bhigi bhi.
Golu chillaaya: “Arre! Meri cycle ki chain, ghanti aur handle pe yeh bhoori-laal cheez kya lag gayi? Aur gate pe bhi!” Usne ungli ragdi toh haath pe naarangi-bhoora powder aa gaya.
Rohan bola: “Lagta hai mitti jam gayi. Dho de, saaf ho jaayegi.” Priya ne apna steel ka tiffin dikhaya: “Par mera tiffin bhi toh roz paani se dhulta hai, uspe toh kabhi kuch nahi laga. Aur yeh powder ragadne se bhi neeche phir se bhoora hi nikal raha hai!”
Golu ne sir khujaaya: “Toh kya mera loha bimaar ho gaya?” Bahut achha sawaal! Chalo, aaj samajhte hain ki loha jang kyun khata hai, aur ise kaise roka jaa sakta hai. 🔍
✅ Seedha Jawab
Jang koi mitti ya gandagi nahi hai. Jab loha hawa ki oxygen aur paani ya nami, dono ke saath ek saath sampark mein rehta hai, toh loha unke saath chemical reaction karke ek nayi cheez ban jaata hai: iron oxide (paani mila hua), jise hum jang kehte hain. Jang bhurbhura hota hai, jhad jaata hai, aur neeche ka naya loha phir se khul jaata hai. Isliye jang dheere-dheere loha “kha” jaata hai. Namak wala paani is kaam ko aur tez kar deta hai.
🤔 Kyun? Step-by-Step
Zameen ke andar loha lagbhag kabhi shuddh roop mein nahi milta. Woh oxygen ke saath juda hua, patthar jaisi cheez (iron ore, jaise haematite) ke roop mein milta hai. Factory mein bahut garmi aur energy laga ke us ore se oxygen alag karke hum chamakdaar loha banate hain.
Kyun yeh zaroori? Kyunki iska matlab hai ki loha mauka milte hi oxygen se phir se judna chahta hai. Jang lagna ek tarah se loha ka apne “purane ghar” (ore jaisi haalat) mein wapas jaana hai.
Humare aas-paas ki hawa ka lagbhag paanchwaan hissa (lagbhag 21%) oxygen hai. Matlab loha jahan bhi rakha ho, oxygen uske paas maujood hai.
Kyun phir har loha turant jang nahi khata? Kyunki sirf oxygen kaafi nahi. Ek “madadgaar” chahiye: paani.
Jab lohe ki satah pe paani ki patli parat ya nami hoti hai, toh loha apne kuch chhote-chhote charge wale kan (electrons) chhod deta hai. Paani unhe oxygen tak pahunchane ka raasta deta hai. Is lena-dena se loha, oxygen aur paani milke jang bana dete hain.
Kyun paani zaroori? Socho, do dost nadi ke do kinaaron pe khade hain aur saamaan dena hai. Pul ho toh lena-dena aasaan. Sookhi hawa mein yeh “pul” nahi hota, isliye sookhe lohe pe jang bahut-bahut dheere lagta hai.
Jang ka asli naam hai iron oxide (jisme paani bhi juda hota hai). Iska rang bhoora-laal hai, yeh bhurbhura hai, chumbak se loha jitna nahi chipakta aur loha jaisa mazboot bhi nahi. Matlab gun (properties) bilkul badal gaye.
Kyun yeh “chemical change” kehlata hai? Kyunki ek nayi cheez bani jiske gun alag hain, aur use wapas aasaani se loha nahi banaya jaa sakta. (Barf pighalna aisa nahi: woh sirf roop badalta hai.)
Jang ki parat chhed-dar aur bhurbhuri hoti hai, aur original lohe se kai guna zyada jagah gherti hai. Isliye woh phool ke phat jaati hai aur papdi ki tarah jhad jaati hai. Neeche ka naya loha phir hawa aur paani ke saamne aa jaata hai, aur jang aur andar tak badhta jaata hai.
Kyun yeh khatarnaak? Jaise roti ke upar se ek parat utaro toh neeche wali dikhne lagti hai. Saalon tak aisa chalta rahe toh lohe ki chaadar mein chhed ho jaate hain aur gate, pul ya railing kamzor ho jaate hain.
Samundar ke kinaare wale shehron (jaise Mumbai, Chennai) mein hawa mein nami aur namak dono zyada hote hain, isliye wahan gaadiyan aur gate jaldi jang khaate hain. Namak paani mein ghul ke us “lena-dena” ko aur aasaan bana deta hai. Garam aur geela mausam bhi reaction ko tez karta hai.
Kyun namak se tez? Namak wala paani charge wale kanon ko bahut aasaani se idhar-udhar le jaata hai, toh “pul” aur chauda ho jaata hai. Isi liye sardi mein jahan sadkon pe namak daala jaata hai, wahan bhi gaadiyon mein jang zyada lagta hai.
Agar loha hawa aur paani tak pahunch hi na paaye, toh jang nahi lagega. Isliye hum lohe pe paint karte hain, tel ya grease lagate hain, ya uspe zinc ki parat chadha dete hain (isse galvanisation kehte hain). Steel mein chromium milaake stainless steel banaya jaata hai.
Kyun yeh kaam karta hai? Paint aur tel ek “raincoat” ki tarah hain. Zinc toh aur bhi samajhdaar hai: parat mein khrosch aa jaaye, tab bhi zinc khud pehle reaction karke lohe ko bachata hai.
Ek line mein: Loha + oxygen + paani (teeno ek saath) = jang. Paani ya oxygen mein se ek bhi hata do, toh jang lagna lagbhag ruk jaata hai. 🔩
🖼️ Picture se Samjho
📕 Textbook Yeh Nahi Batata
1. Jang lagne se loha “bhaari” ho jaata hai! Lagta hai jang loha kha raha hai toh vajan kam hoga. Par ulta hota hai: jang mein loha ke saath hawa ki oxygen (aur paani) bhi jud jaati hai. Hisaab lagao toh 10 gram loha poora jang ban jaaye toh kam se kam lagbhag 14 gram jang banega, aur paani judne se usse bhi zyada. Woh extra vajan hawa se aaya! (Haan, jo jang jhad ke gir gaya, woh cheez se alag ho gaya, isliye gate patla hota dikhta hai.)
2. Delhi ka 1600 saal purana loha ka khamba. Delhi mein Qutub Minar parisar mein lohe ka ek khamba hai jo lagbhag 1600 saal se khule mein khada hai, 7 metre se zyada lamba, phir bhi us pe bahut kam jang hai. Vaigyanik bataate hain ki iske lohe mein phosphorus thoda zyada hai, jisse satah pe ek patli, chipki hui suraksha parat ban gayi jo aage jang ko rokti hai. Matlab hazaaron saal pehle bhi Bharat ke kaarigar kamaal ka loha banate the! 🇮🇳
3. Jang lagna garmi bhi deta hai. Yeh reaction thodi garmi chhodta hai, par itna dheere hota hai ki hum mehsoos nahi karte. Thande deshon mein milne wale kuch “hand warmer” packet isi ka tez version use karte hain: andar ke lohe ke bareek powder ko hawa milte hi woh garam ho jaate hain.
🚫 Log Aisa Sochte Hain… Lekin
✅ Lekin: jang bahar se nahi aaya; yeh lohe ka hi badla hua roop hai. Isliye dhone se nahi jaata, aur ragadne pe neeche bhi bhoora hi nikalta hai.
✅ Lekin: paani ke saath oxygen bhi chahiye. Tel ki parat wale ubale paani mein (jahan hawa lagbhag nahi pahunchti) keel ko bahut hi kam ya koi jang nahi lagta.
✅ Lekin: aam steel (jisse sariya, gate, cycle ka frame bante hain) bhi jang khata hai. Sirf stainless steel jang se bachta hai, kyunki usmein chromium milaya jaata hai. Isi liye Priya ka tiffin chamakta hai!
✅ Lekin: jang bhurbhura aur chhed-dar hai, jhad jaata hai. Woh suraksha nahi deta, balki nami ko pakad ke rakhta hai aur andar tak jang badhne deta hai.
🏠 Ghar ka Mini Experiment: “Keelon ki Jang Race”
Ek hafte ka experiment! Hum dekhenge ki jang ke liye kya-kya chahiye.
Saamaan: 4 nayi saadi lohe ki keelein (hardware dukaan se; chamakdaar silver “galvanised” wali nahi), 4 saaf glass ki chhoti bottle ya transparent plastic ke glass, nal ka paani, ek chammach namak, thoda khaane ka tel, ek band dhakkan wali sookhi bottle, sticker ya kaagaz pe naam likhne ke liye pen.
Kya seekha aur kyun: D (namak-paani) mein sabse jaldi aur sabse zyada jang lagega, phir A mein, kyunki wahan loha, oxygen aur paani teeno hain, aur namak reaction ko tez karta hai. B mein bahut kam ya bilkul nahi lagega, kyunki ubalne se paani ki hawa nikal gayi aur tel ne nayi hawa ko ghusne nahi diya. C mein bhi lagbhag nahi lagega, kyunki wahan nami nahi hai. Sabak: teeno saath honge tabhi jang lagega!
🌍 Real Life Mein
- Cycle ki chain pe tel: chain mein tel ya grease isliye daalte hain taaki woh aasaani se chale aur saath hi hawa-paani se bachi rahe. Barsaat ke baad cycle ko kapde se ponchh ke rakhna jang se bachata hai.
- Gate aur grill pe paint: har kuch saal mein gate pe naya paint isliye karte hain, kyunki purane paint mein daraar aate hi wahan se jang shuru ho jaata hai.
- Chamakdaar paani ki tanki aur balti: lohe ki balti ya chhat ki chaadar pe zinc ki parat hoti hai (galvanised). Isliye woh silver-grey dikhti hain aur saalon chalti hain.
- Rasoi ki kadhai: lohe ki kadhai dhone ke baad turant sukha ke usme halka sa tel laga dete hain. Ab aap jaante ho kyun: nami hatao, tel ki parat lagao, jang gaayab!
- Imaaraton ka sariya: concrete ke andar ke lohe ke sariye mein jang lag jaaye toh jang phool ke concrete ko andar se tod deta hai. Isliye samundar ke paas ki imaaraton mein khaas dhyan rakha jaata hai.
🔗 NCERT Connection
Yeh topic Class 8 Science (Curiosity) ke is chapter se judta hai:
- Chapter 8: Nature of Matter: Elements, Compounds, and Mixtures: loha ek element hai, aur jang ek compound (loha + oxygen, saath mein paani) jiske gun lohe se bilkul alag hain. Padho: Chapter 8 (CharuMam)
Class 7 mein aapne physical aur chemical changes wale chapter mein bhi jang ke baare mein padha hoga: jang lagna ek chemical change ki sabse achhi misaal hai.
Saare chapters ki list: Class 8 Science (CharuMam)
📝 Recap
- Jang = iron oxide (paani mila hua), bhoore-laal rang ki bhurbhuri cheez.
- Jang ke liye loha + oxygen + paani/nami, teeno ek saath chahiye.
- Jang lagna ek chemical change hai: nayi cheez, naye gun.
- Jang jhad jaata hai, naya loha khulta hai, isliye loha dheere-dheere khatm hota hai.
- Namak, nami aur garmi jang ko tez karte hain; paint, tel/grease, zinc ki parat (galvanisation), stainless steel isse rokte hain.
🎯 Quiz (5 MCQ)
1. Lohe pe jang lagne ke liye kya zaroori hai? (a) Sirf paani (b) Sirf hawa ki oxygen (c) Oxygen aur paani dono (d) Sirf tez dhoop
✅ (c): jang tabhi lagta hai jab loha oxygen aur paani dono ke sampark mein ho. (a) Galat: bina oxygen ke (jaise tel ki parat wala ubala paani) jang lagbhag nahi lagta. (b) Galat: sookhi hawa mein “pul” ka kaam karne wala paani nahi, toh jang bahut-bahut dheere. (d) Galat: dhoop zaroori nahi; andhere geele kone mein bhi jang lagta hai.
2. Jang asal mein kya hai? (a) Sodium chloride (b) Iron oxide (paani mila hua) (c) Lohe pe jami mitti (d) Carbon dioxide
✅ (b): jang loha, oxygen aur paani se bani nayi cheez, iron oxide hai. (a) Galat: sodium chloride toh khaane ka namak hai. (c) Galat: jang bahar se nahi aata, lohe ka hi badla roop hai. (d) Galat: carbon dioxide ek gas hai, jang thos hai.
3. Samundar kinaare ke shehar mein cycle jaldi jang kyun khaati hai? (a) Wahan dhoop kam hoti hai (b) Wahan ka loha naram hota hai (c) Samundar ki lehron ki awaaz se (d) Hawa mein nami aur namak zyada hota hai
✅ (d): zyada nami aur hawa mein namak, dono jang ko tez karte hain. (a) Galat: dhoop ka jang se seedha lena-dena nahi. (b) Galat: loha har jagah ek jaisa hi hai, jagah se naram nahi hota. (c) Galat: awaaz se koi chemical reaction nahi hota.
4. 10 gram loha poora jang ban jaaye, toh bane hue jang ka vajan kitna hoga? (a) 10 gram se kam (b) Theek 10 gram (c) 10 gram se zyada (d) Zero, loha gaayab ho jaayega
✅ (c): jang mein lohe ke saath oxygen (aur paani) bhi jud jaate hain, toh vajan badhta hai (kam se kam lagbhag 14 gram). (a) Galat: kuch ghata nahi, balki juda. (b) Galat: nayi cheezein judi hain, toh barabar nahi reh sakta. (d) Galat: loha gaayab nahi hota, jang ke andar maujood hai.
5. Galvanisation mein lohe pe kis dhaatu ki parat chadhayi jaati hai? (a) Zinc (b) Sona (c) Taamba (d) Chaandi
✅ (a): zinc ki parat chadhane ko galvanisation kehte hain; zinc khud pehle reaction karke lohe ko bachata hai. (b) Galat: sona bahut mehenga hai, aam suraksha ke liye nahi lagta. (c) Galat: taamba galvanisation mein use nahi hota. (d) Galat: chaandi bhi mehengi hai aur yeh tareeka nahi kehlata.
🧠 Socho aur Batao
1. Ek jaisa lohe ka gate Jaisalmer (registan) mein aur ek Mumbai (samundar kinaare) mein laga hai. Kiska gate jaldi jang khaayega, aur kyun?
Mumbai wala. Jang ke liye paani/nami chahiye. Registan ki hawa bahut sookhi hoti hai aur baarish kam, toh wahan “pul” ka kaam karne wala paani kam milta hai. Mumbai mein hawa mein nami bahut zyada hai, baarish bhi bahut hoti hai, aur samundar ki hawa mein namak ke bareek kan bhi hote hain. Nami + namak = tez jang. (Isi liye registan jaisi sookhi jagahon pe purani lohe ki cheezein bhi kaafi achhi haalat mein mil jaati hain.)
2. Ek paint kiye hue gate aur ek zinc wale (galvanised) gate, dono pe gehri khrosch (scratch) lag gayi. Kis gate mein khrosch ke paas jaldi jang lagega?
Paint wale gate mein. Paint sirf ek “raincoat” hai: khrosch se loha khul gaya toh wahan hawa-paani pahunch ke jang shuru kar denge, aur jang paint ke neeche bhi failne lagta hai. Galvanised gate mein zinc ki parat khrosch ke aas-paas bhi lohe ko bachati rehti hai, kyunki zinc lohe se pehle khud reaction karta hai (woh “bodyguard” ki tarah khud chot kha leta hai). Isliye khrosch ke baad bhi wahan jang der se lagta hai.
❓ FAQ
1. Stainless steel ke bartan jang kyun nahi khaate?
Stainless steel mein loha ke saath chromium (aur aksar nickel) milaya jaata hai. Chromium hawa se milke satah pe ek bahut patli, na dikhne wali, mazboot parat bana deta hai jo hawa-paani ko andar ke lohe tak pahunchne nahi deti. Parat ghis bhi jaaye toh chromium use phir se bana leta hai. Isliye tiffin, chammach, sink saalon chamakte rehte hain.
2. Kya sona, chaandi ya taamba bhi jang khaate hain?
“Jang” shabd asal mein sirf lohe (aur steel) ke liye hai. Doosri dhaatuen bhi hawa se dheere-dheere badalti hain: taambe pe hari parat aa jaati hai, chaandi kaali pad jaati hai. Ise milaake corrosion kehte hain. Sona lagbhag bilkul nahi badalta, isliye hazaaron saal purane sone ke gehne bhi chamakte milte hain. Taambe ke bartan nimbu se kyun chamakte hain, yeh hum SN-43 mein dekhenge!
3. Kya jang lagi keel se chot lagne pe beemari jang ki wajah se hoti hai?
Aisa nahi hai ki jang khud beemari deta hai. Mitti aur gandagi mein kuch keetanu (bacteria) hote hain jo kisi bhi gandi, nukeeli cheez ki chot se sharir mein ja sakte hain, aur purani jang lagi keelein aksar gandi jagah padi milti hain. Isliye kisi bhi nukeeli cheez se chot lage toh turant ghar ke bade ko batao, ghaav saaf karwao, aur aage kya karna hai, yeh doctor ki salah se hi tay karein.
💖 CharuMam Motivation
Loha bahut mazboot hai, phir bhi agar use mahino tak bina dekhbhaal ke baarish mein chhod do, toh chhoti-chhoti nami usko andar se kamzor kar deti hai. Aur ek pyaari si baat: thoda sa tel, thoda sa paint, thodi si fikar, aur wahi loha saalon-saal chamakta hai.
Beta, aapki achhi aadatein aur aapka seekha hua gyaan bhi aise hi hai. Roz thoda padhna, roz thoda doharana, yeh aapke dimaag ki “paint ki parat” hai. Ek din chhod diya toh kuch nahi bigadta, par lambe samay tak bhool gaye toh jang lagne lagta hai. Toh roz thodi-thodi dekhbhaal karte raho; aap bhi Delhi ke us khambe ki tarah saalon tak mazboot aur chamakdaar rahoge. 🔩✨
— CharuMam
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