In the precipitation titration of KCl against AgNO₃, K₂CrO₄ is used as an indicator since, AgCl is white coloured. End point is detected by appearance of deep yellow coloured precipitate of Ag₂CrO₄. The minimum concentration of chromate ion required for detection of end point is : \(\left[\mathrm{K}_{\text {sp }} \text { of } \mathrm{AgCl}=2.5 \times 10^{-10} \text { and } \mathrm{K}_{\text {sp }} \text { of } \mathrm{Ag}_2 \mathrm{CrO}_4=1.8 \times 10^{-12}\right]\)
1. \(7.3 \times 10^{-2} ~\mathrm{M} \)
2. \(5 .3 \times 10^{-4}~ \mathrm{M} \)
3. \(7 .3 \times 10^{-3} ~\mathrm{M} \)
4. \(3.6 \times 10^{-5}~ \mathrm{M}\)

The concentration of hydroxyl ion in a solution left after mixing 100 mL of 0.1 M MgCl₂ and 100 mL of 0.2 M NaOH is: $[{\mathrm{K}}_{\mathrm{sp}}<mspace\; width="1em"></mspace>\mathrm{of}<mspace\; width="1em"></mspace>\mathrm{Mg}{\left(\mathrm{OH}\right)}_2=1.2\times {10}^{-11}]$ 

1. $2.8\times {10}^{-3}$

2. $2.8\times {10}^{-2}$

3. $2.8\times {10}^{-4}$

4. $2.8\times {10}^{-5}$

A solution containing NH₄Cl and NH₄OH has a hydroxide ion concentration of ${10}^{-6}<mspace\; width="1em"></mspace>\mathrm{mol}<mspace\; width="1em"></mspace>{\mathrm{litre}}^{-1}$, which of the following hydroxides could be precipitated when this solution is added in equal volume of a solution containing 0.1 M of metal ions?
1. \(\mathrm{AgOH}\left(\mathrm{K}_{\mathrm{sp}}=5 \times 10^{-3}\right) \)
2. \(\mathrm{Cd}(\mathrm{OH})_2\left(\mathrm{~K}_{\mathrm{sp}}=8 \times 10^{-6}\right) \)
3. \(\mathrm{Mg}(\mathrm{OH})_2\left(\mathrm{~K}_{\mathrm{sp}}=3 \times 10^{-11}\right) \)
4. \(\mathrm{Fe}(\mathrm{OH})_2\left(\mathrm{~K}_{\mathrm{sp}}=8 \times 10^{-16}\right)\)

Hydrolysis constant \(K_h\) of two salts of weak acids HA and HB are 10^-8 and 10^-6 respectively. If the dissociation constant of the third acid HC is 10^-2.
The order of acidic strengths of three acids will be :

1. HA>HB>HC

2. HB>HA>HC

3. HC>HA>HB

4. HA=HB=HC

The percentage hydrolysis of NaCN in \(( {N \over 80})\) aqueous solution is :
[Dissociation constant of \(\mathrm{HCN}=1.3 \times 10^{-9} \text { and } \mathrm{K}_{\mathrm{w}}=1.0 \times 10^{-14}\)${\mathrm{}}^{}$]

When equal volume of the following solutions are mixed, which of the following gives maximum precipitate?
\((K_{sp}~ \text {of} ~AgCl = 10^{-12})\) $$

1. \(10^{-4} \mathrm{M}~ \mathrm{Ag}^{+}~\text {and} ~10^{-4} ~\mathrm{M}~ \mathrm{Cl}^{-}\)
2. \(10^{-3} \mathrm{M} ~\mathrm{Ag}^{+} \text {and }10^{-3} \mathrm{M} ~\mathrm{Cl}^{-}\)
3. \(10^{-5} \mathrm{M}~ \mathrm{Ag}^{+}~\text {and }10^{-5} \mathrm{M} ~\mathrm{Cl}^{-}\)
4. \(10^{-6} \mathrm{M} ~\mathrm{Ag}^{+}~\text {and }~10^{-6} \mathrm{M} ~\mathrm{Cl}^{-}\)

0.1 M solution of three different sodium salts NaX, NaY and NaZ have pH values 7.0, 9.0 and 11.0 respectively. The correct order of dissociation constant values of these acids is :

1. K_HX<K_HY<K_HZ

2. K_HX>K_HY>K_HZ

3. K_HX>K_HZ>K_HY

4. K_HX<K_HY<K_HZ

Silver acetate is a slightly soluble salt of a weak acid $({\mathrm{K}}_{\mathrm{a}}=1.75\times {10}^{-5})$. At $25°\mathrm{C}$, 100 g of water dissolves 1.04 g of crystalline silver acetate. The density of saturated solution of silver acetate at $20°\mathrm{C}$ is 1.01 g/cc. The solubility product constant for silver acetate at $20°\mathrm{C\; will\; be:}$

1. $2.43\times {10}^{-3}$

2. $3.87\times {10}^{-3}$

3. $7.74\times {10}^{-5}$

4. $1.35\times {10}^{-5}$

Separate solutions of four sodium salts NaW, NaX, NaY and NaZ had pH 7.0, 9.0, 10.0 and 11.0 respectively. When each solution is 0.1 M, the strongest acid is

1. HW

2. HX

3. HY

4. HZ