Which of these can not be a Bronsted acid?

1. ${\mathrm{HCO}}_3^{-}$

2. ${\mathrm{HCOO}}^{-}$

3. ${\mathrm{H}}_2{\mathrm{PO}}_3^{-}$

4. ${\mathrm{H}}_3{\mathrm{O}}^{+}$

Find the correct order of proton-accepting tendency (Brønsted basic strength) among HS⁻, I⁻, RNH₂, and NH₃.

Which one of the following orders of acid strength is correct?

1. $\mathrm{RCOOH}>\mathrm{HC}\equiv \mathrm{CH}>\mathrm{HOH}>\mathrm{ROH}$

2. $\mathrm{RCOOH}>\mathrm{ROH}>\mathrm{HOH}>\mathrm{HC}\equiv \mathrm{CH}$

3. $\mathrm{RCOOH}>\mathrm{HOH}>\mathrm{ROH}>\mathrm{HC}\equiv \mathrm{CH}$

4. $\mathrm{RCOOH}>\mathrm{HOH}>\mathrm{HC}\equiv \mathrm{CH}>\mathrm{ROH}$

A centinormal solution of a monobasic acid is 100% ionized. Its pH is:

1. 2

2. 4

3. 3

4. 1

Find the mixture that can act as a buffer solution.

Which one of the following statements is not correct?

At \(90^\circ \text C,\) pure water has \([H_3O^+]=10^{-6}~\text{mole litre}^{-1}.\) What is the value of \(K_w\) at \(90^\circ \text C?\)

Find the strongest Brønsted base among the following anions:

What is the pH of a 10⁻⁸ M solution of HCl in water?

1. -8

2. 8

3. between 6 and 7

4. between 7 and 8

Find the pair of solutions that can be mixed to prepare an acidic buffer.

1. Sodium chloride and sodium hydroxide

2. Sulphuric acid and sodium sulphate

3. Ammonium chloride and ammonium nitrate

4. Ammonium acetate and acetic acid