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

Blood is a colloidal solution where the blood particles (proteins and cells) carry a negative charge. When blood flows from a wound, efficient clotting (coagulation) requires the neutralisation of these negative charges by positively charged ions.

According to the Hardy-Schulze rule, the coagulating power of an electrolyte increases with the valency of the ion carrying the charge opposite to that of the colloidal particles. Since blood is a negatively charged colloid, we need cations (positive ions) to cause coagulation, and the higher the valency of the cation, the greater the coagulating power.

Examining the given options: $$FeCl_3$$ provides $$Fe^{3+}$$ (trivalent cation), $$Mg(HCO_3)_2$$ provides $$Mg^{2+}$$ (divalent cation), $$FeSO_4$$ provides $$Fe^{2+}$$ (divalent cation), and $$NaHCO_3$$ provides $$Na^+$$ (monovalent cation).

Since $$Fe^{3+}$$ has the highest valency (+3) among all the cations listed, $$FeCl_3$$ will have the greatest coagulating power and will be the most suitable salt for efficient clotting of blood.

Therefore, the correct answer is Option (1): $$FeCl_3$$.