Question

Which is the correct thermal stability order for H₂E (E = 0, S, Se, Te and Po)?

Options

• H₂S < H₂O < H₂Se < H₂Te < H₂Po

• H₂O < H₂S < H₂Se < H₂Te < H₂Po

• H₂Po < H₂Te < H₂Se < H₂S < H₂O

• H₂Se < H₂Te < H₂Po < H₂O < H₂S

Answer 1

H₂Po < H₂Te < H₂Se < H₂S < H₂O

Explanation:

As we move down the group from oxygen to polonium, the size of the central atom increases, weakening the M-H bond and thus decreasing the thermal stability. Water (H₂O) has the highest thermal stability due to strong hydrogen bonding, while the stability decreases progressively down to H₂Po.