100 mL of 0.1 M HCl is taken in a beaker and to it 100 mL of 0.1 M NaOH is added in steps of 2 mL and the pH is continuously measured. Which of the following graphs correctly depicts the change in pH?

1.		2.
3.		4.

Consider the following statements

The correct statements are:
1. (a) and (b)

2. (a), (b) and (c)

3. (a) and (c)

4. (b) and (c)

The conjugate base of \(H_2PO_{4}^{-}\) is:

1. \(PO_{4}^{3-}\)

2. \(P_2O_5\)

3. \(H_3PO_4\)

4. \(HPO_{4}^{2-}\)

The species, among the following, that act as both Brönsted acid and base is/are:

1. \(H_2PO^-_2 \) 

2.  \(HPO^{2-}_3\)

3. \(HPO^{2-}_4\)

4. All of the above