Question

Most suitable salt which can be used for efficient clotting of blood will be :

• A. NaHCO₃
• B. Mg(HCO₃)₂
• C. FeCl₃
• D. FeSO₄

Hint:

Hardy-Schulze Rule: Higher valency = Faster coagulation. $Al^{3+}>Mg^{2+}>Na^+$ for negative sols.

Answer 1

The Correct Option is C

Step 1: Blood is a negatively charged colloidal solution (sol).
Step 2: According to the Hardy-Schulze rule, the coagulating power of an electrolyte is directly proportional to the fourth power of the valency of the active ion.
Step 3: Among the options, $Fe^{3+}$ (from $FeCl_3$) has the highest positive charge compared to $Na^+$, $Mg^{2+}$, and $Fe^{2+}$.
Step 4: Therefore, $FeCl_3$ is the most effective at neutralizing the negative charge on blood particles, causing rapid clotting (coagulation).