The correct answer is Option A.
The calculation goes as follows:
Number of millimoles of Na3PO4 = 1 × 100 = 100
Number of millimoles of AgNO3 = 1 × 100 = 100
Dissociating 1 mole of Na3PO4 yields 3 moles of sodium ions and 1 mole of phosphate ions, whereas 1 mole of AgNO3 releases 1 mole of Ag+ and 1 mole of NO3-.
The Ag+ ion concentration becomes negligible since it forms a precipitate with the phosphate ion, indicating that the concentration of phosphate ions is also low.
With 100 millimoles of Na3PO4, we get 300 millimoles of Na+ and 100 millimoles of PO43-, and with 100 millimoles of AgNO3 we have 100 millimoles of Ag+ and 100 millimoles of NO3-.
Thus, the order of increasing concentration is: PO43- < NO3- < Na+.
The correct answer is option (D): CO₂, BCl₃, and Fe³⁺.
Lewis theory defines an acid as a substance that can accept electron pairs, while a base donates electron pairs.
a. It’s a Lewis acid as it accepts electron pairs.
b. It isn't a Lewis acid since it does not accept electron pairs, but serves as a base by donating and accepting hydrogen ions.
c. This qualifies as a Lewis acid as it accepts electron pairs due to having an incomplete octet and empty 2p orbitals.
d. This is categorized as a Lewis acid as it accepts electron pairs.
Therefore, the ions recognized as Lewis acids include CO₂, BCl₃, and Fe³⁺.
