Which of the following sequences correctly represents the increasing order of acidic strength?

1. HClO₂ < HClO₃ < HClO₄

2. H₃PO₄ < H₃PO₃ < H₃PO₂

3. CH₄ < NH₃ < H₂O < HF

4. All of the above.

Which of the following is a common use of sulphuric acid?

Which of the following correctly represents the order of boiling points of the given substances?

1. H₃PO₄ < H₂SO₄

2. H₂O > H₂O₂

3. H₂O > SiC

4. NH₃ > HF

Which of the following orders is incorrect for the given properties of halogens?

Which of the following Group 16 hydrides has the lowest boiling point?

1. ${\mathrm{H}}_2\mathrm{O}$

2. ${\mathrm{H}}_2\mathrm{S}$

3. ${\mathrm{H}}_2\mathrm{Se}$

4. ${\mathrm{H}}_2\mathrm{Te}$

Which of the following hydrides is the least poisonous?

1. ${\mathrm{NH}}_3$

2. ${\mathrm{PH}}_3$

3. ${\mathrm{AsH}}_3$

4. ${\mathrm{SbH}}_3$

Which of the following  hydrides has the lowest pKa value?

1. H₂O

2. H₂S

3. H₂Se

4. H₂Te

Which of the following Group 15 elements does not form a stable pentoxide?

1. As
2. Sb
3. Bi
4. P