Displacement & Double Displacement 🔁

Jagah Badalne Wali Reactions 🔁

Ab do aur types - jinme atoms ya ions apni jagah badal lete hain. Ek mein ek metal (dhaatu) doosri ko hataati hai, aur doosri mein do compounds aapas mein apne hisse badal lete hain.

1️⃣ Displacement Reaction (Displacement)

📌 Jab ek zyada reactive element (tatva) kisi compound (yaugik) se kam reactive element ko hata (displace) deta hai.
Pattern: A + BC → AC + B

🔵 Neela Ghol Hara Kaise Hua?

Lab mein copper sulphate ka chamakdaar neela ghol lo aur usme ek saaf lohe ki keel daal do. Ab 20-30 minute intezaar karo. Kya hota hai? Ghol ka neela rang dheere-dheere hara ho jaata hai, aur keel par ek bhoori-laal parat jam jaati hai! Kyun? Kyunki loha copper se zyada reactive hai - usne copper ko uski jagah se hata diya aur khud ghol mein baith gaya. Wo bhoori parat = shuddh copper!

✔ Displacement (visthapan) ke examples

1. Loha + copper sulphate (neela → hara):
Fe(s) + CuSO₄(aq) → FeSO₄(aq) + Cu(s)

2. Zinc + copper sulphate:
Zn(s) + CuSO₄(aq) → ZnSO₄(aq) + Cu(s)

3. Lead + copper chloride:
Pb(s) + CuCl₂(aq) → PbCl₂(aq) + Cu(s)

⚠️ Ulta nahi hoga! Copper ki taar ko ferrous sulphate ke ghol mein daaloge toh kuch nahi hoga - kyunki copper lohe se kam reactive hai, wo lohe ko hata hi nahi sakta. Board mein ye "reason do" wala sawaal aata hai.

📊 Reactivity Series (yaad rakhne layak)

K > Na > Ca > Mg > Al > Zn > Fe > Pb > H > Cu > Hg > Ag > Au
Jo upar hai wo neeche waale ko hata sakta hai. Isi list se pata chalta hai kaunsi displacement hogi aur kaunsi nahi. (Iski poori detail Chapter 3 - Metals and Non-metals mein.)

2️⃣ Double Displacement Reaction (Double displacement)

📌 Jab do compounds aapas mein apne ions ki adla-badli kar lete hain.
Pattern: AB + CD → AD + CB

1️⃣ SINGLE — ek partner badalta hai Fe + CuSO₄ → FeSO₄ + Cu Neela CuSO₄ Hara FeSO₄ + Cu 🟤 Zyada reactive metal kam wale ko hataati hai 2️⃣ DOUBLE — dono partner badalte hain Na₂SO₄ + BaCl₂ → BaSO₄↓ + 2NaCl safed PRECIPITATE Precipitation reaction (abhikriya) = double displacement jisme ek product paani mein ghulta nahi (↓)
Single displacement mein ek partner badalta hai, double mein dono — aur aksar ek precipitate girta hai.

✔ Classic example - peela precipitate

Lead nitrate ka saaf ghol + potassium iodide ka saaf ghol milaao, aur turant ek chamakdaar peela padarth ban kar neeche baith jaata hai:
Pb(NO₃)₂(aq) + 2KI(aq) → PbI₂(s)↓ + 2KNO₃(aq)
Yahan Pb aur K ne apni jagah badal li. PbI₂ paani mein nahi ghulta, isliye wo thos bankar baith gaya.

⬇️ Precipitation Reaction (Avakshepan)

Double displacement ka wo khaas roop jisme ek na-ghulne wala thos padarth banta hai, use precipitation reaction kehte hain, aur us thos ko precipitate (avakshep) kehte hain. Ise ↓ se dikhaya jaata hai.

✔ Aur precipitation examples

Sodium sulphate + Barium chloride (safed precipitate):
Na₂SO₄(aq) + BaCl₂(aq) → BaSO₄(s)↓ + 2NaCl(aq)

PrecipitateRang
PbI₂ (lead iodide)Peela (yellow)
BaSO₄ (barium sulphate)Safed (white)
AgCl (silver chloride)Safed
Cu(OH)₂ (copper hydroxide)Neela (blue)
Fe(OH)₃ (iron hydroxide)Bhoora (brown)
💧 Rozmarra Mein Precipitation

Aapke bathroom ki tanki ya nal par jo safed-sa jamav dikhta hai, wo bhi ek tarah ka precipitate hai - kade paani (hard water) mein ghule calcium/magnesium salts jamkar baith jaate hain. Water treatment plants mein bhi gande paani ki safai ke liye jaan-boojh kar precipitation reactions karayi jaati hain, taaki gandagi thos bankar neeche baith jaaye.

🧭 Type Pehchaanne Ka Aasaan Tareeka

DekhoType
Kai reactants → ek productCombination (sanyojan)
Ek reactant → kai productsDecomposition (viyojan)
Ek element + ek compoundDisplacement
Do compounds, ions ki adla-badliDouble displacement
Double displacement + thos (↓) banaPrecipitation

🧠 Apne Aap Ko Test Karo

Q1. Fe + CuSO₄ → FeSO₄ + Cu kaunsi reaction hai?
Q2. Lead nitrate + potassium iodide milane par kis rang ka precipitate banta hai?
Q3. Copper ki taar ko FeSO₄ ke ghol mein daalne par kya hoga?

🧊 3D mein dekho atoms kaise jagah badalte hain - aur ek bhi atom kam nahi hota!

Open 3D Reaction Lab →