Foundations — Common ion effect

2.6.13 · D1 · Chemistry › Equilibrium › Common ion effect

#chemistry/equilibrium #solubility #foundations

Is page par assume kiya gaya hai ki tumhe kuch nahi pata. Parent note padhne se pehle, usmein use kiya gaya har letter, arrow, aur squiggle tumhare liye kuch concrete mean karna chahiye. Hum unhe ek ek karke build karte hain, har ek pichle par. Koi cheez use nahi hoti jab tak draw na ho.

Symbol 0 — substances: "salt", "sparingly soluble", "(s)" aur "(aq)"

Picture. Figure ke left half mein dekho: ions ka ek solid block. Right half mein: wohi ions toot ke alag ho gaye hain aur paani mein drift kar rahe hain, har ek chhote paani ke molecules se hugged.

Topic ko isko kyun chahiye. Poori kahani ek solid (s) ke free ions (aq) mein badle jaane ke baare mein hai aur wapas. Agar tum in do states mein fark nahi kar sakte, toh baad ke arrows ka koi matlab nahi.

Symbol 1 — square brackets $[]$ : concentration

Picture. Ek fixed 1-litre box imagine karo. Concentration = uus box ke andar kitne red dots count kar sakte ho. Zyada dots cramped = bada $[\text{X}]$.

Symbol 2 — superscripts ${\text{Ag}}^{+}$, ${\text{Cl}}^{-}$, ${\text{Pb}}^{2+}$ : charge

Picture. Ek $+$ atom aur ek $-$ atom ek doosre ki taraf khichte hain (opposite charges attract) — wohi pull unhe solid grid mein chipkaya tha, aur wahi solid dobara banta hai jab woh paani mein milte hain.

Topic ko isko kyun chahiye. "Common ion" charge aur identity se define hota hai. Salt A ka ${\text{Cl}}^{-}$ aur salt B ka ${\text{Cl}}^{-}$ same particle hai — paani unhe alag nahi kar sakta. Wohi "sameness" poora trick hai.

Symbol 3 — double arrow $\rightleftharpoons$ : equilibrium

Picture. "Solid room" aur "dissolved room" ke beech do darwaze. Log upar waale darwaze se baahir jaate hain aur neeche waale se wapas aate hain. Jab har second mein equal log dono taraf jaayein, toh har room ki bheed frozen lagti hai — bhaale sab log ab bhi chal rahe hon.

$\text{AgCl(s)}\rightleftharpoons {\text{Ag}}^{+}\text{(aq)}+{\text{Cl}}^{-}\text{(aq)}$

Ise abhi ek sentence ki tarah padho: "Solid silver chloride, same rate par, free ${\text{Ag}}^{+}$ aur free ${\text{Cl}}^{-}$ mein toot raha hai, aur unse wapas ban raha hai."

Symbol 4 — solubility $s$

Picture. Doors balance hone ke baad "dissolved room" ki bheed ka size. Bada $s$ = bahut dissolved; tiny $s$ (sparingly soluble) = almost khali dissolved room.

Symbol 1 se link. $\text{AgCl}$ ke liye, jo solid unit dissolve hoti hai woh exactly ek ${\text{Ag}}^{+}$ aur ek ${\text{Cl}}^{-}$ release karti hai. Toh agar $s$ mol/L dissolve hua: $[{\text{Ag}}^{+}]=s[{\text{Cl}}^{-}]=s$ Solubility ($s$, solid ki property) aur concentration ($[]$, paani mein ion ki property) formula ki recipe se linked hain.

Symbol 5 — stoichiometric numbers ($2{\text{Cl}}^{-}$ mein "2")

Picture. Ek ${\text{PbCl}}_2$ brick todo aur do chloride marbles nikalti hain, ek lead marble. Toh agar $s$ bricks dissolve hon: $[{\text{Pb}}^{2+}]=s[{\text{Cl}}^{-}]=2s$

Symbol 6 — equilibrium constant $K_{sp}$

"Product" kyun aur woh powers kyun? Yeh Solubility Product (Ksp) ka equilibrium-constant rule hai: ion crowdedness values ko multiply karo, aur har ion utni baar appear hota hai jitni baar produce hota hai — do chlorides matlab $[{\text{Cl}}^{-}]$ khud se multiply, yaani $[{\text{Cl}}^{-}{]}^2$.

Solid kahan gaya? Solid $\text{AgCl(s)}$ ki constant "purity" hai (activity $=1$), isliye yeh 1 ka factor contribute karta hai aur $K_{sp}$ mein kabhi appear nahi hota. Sirf dissolved ions karte hain.

Symbol 7 — square root  ​ aur primed $s^{\prime }$

Symbol 8 — "much-less-than" sign $\ll$ aur $\approx$

Yeh sab kaise feed karte hain ek doosre mein

Har arrow ek "yeh pehle chahiye usse pehle woh" hai. Koi bhi path upar se neeche trace karo aur tumne parent derivation padhne ka haq kama liya.

Equipment checklist

Cover the right side and answer aloud; reveal to check.

Connections

• Le Chatelier's Principle: backward shift ke peeche "kyun" hai.
• Solubility Product (Ksp): jahan se $K_{sp}$ product rule aata hai.
• Ionic Equilibrium: simultaneous ion balances ki badi duniya.
• Buffer Solutions aur Qualitative Analysis: jagahein jahan yeh foundation use hoti hai.
• Hinglish version →