Dissociation of phosphorus pentachloride is favoured by:

1. High temperature and high pressure

2. High temperature and low pressure

3. Low temperature and low pressure

4. Low temperature and high pressure

1. I, and II

2. II, and III

3. I, and III

4. I,II ,and III

The stability product constant K_sp of Mg(OH)₂ is 9.0 X 10^-12. If a solution is 0.010 M with respect to Mg²⁺ ion, what is the maximum hydroxide ion concentration which could be present without causing the precipitation of Mg(OH)₂ ?

1. 1.5 X 10^-7 M

2. 3.0 X 10^-7 M

3. 1.5 X 10^-5 M

4. 3.0 X 10^-5 M

The amount of CaC₂O₄ (molecular weight =128) will dissolve in distilled water to make 1 liter of a saturated solution is: 

[K_sp (CaC₂O₄) = 2.5 x 10^-9 ]

1. 0.0064 g             
2. 0.1280 g
3. 0.0128 g           
4. 1.2800 g

What substance could be added to one liter of water to serve as a buffer?

1. One mole of \(CH_ 3 COO H\) and 0.5 moles of \(NaOH\)

2. One mole of \(NH_4Cl\) and one mole of \(HCl\)

3. One mole of \(NH_4OH\) and one mole of \(NaOH\)

4. One mole of \(CH_ 3 COO H\) and one mole of \(HCl\)

Acoording to Bronsted-Lowry concept, the correct order of relative strength of bases follows the order

1. CH₃COO^- > Cl^- > OH^-

2. CH₃COO^- > OH^- > Cl^-

3. OH^- > CH₃COO^- > Cl^-

4. OH^- > Cl^-> CH₃COO^-

pOH of H₂O is 7.0 at 298K. If water is heated at 350K, which of the following statement should be true ?

(1) pOH will decrease

(2) pOH will increase

(3) pOH will remain 7.0

(4) Concentration of H⁺ ions will increase but that of OH^- will decrease.

An aqueous solution of NaHSO₃ is-

1. Acidic                 
2. Slightly alkaline
3. Alkaline             
4. Slightly Acidic

The solubility product constant (K_sp) of salts of type MX, MX₂ and M₃X at temperature T are 4.0 X 10^-8, 3.2 X 10^-14 and
2.7 X 10^-15 respectively. The order of solubilities (mol dm^-3) of the salts at temperature T is:

1. MX > MX₂ > M₃X

2. M₃X > MX₂ > MX

3. MX₂ >M₃X >MX > 

4.  MX >M₃X > MX₂

Ostwald dilution law for weak electrolyte HA can be given as

$\left(1\right)<mspace\; width="1em"></mspace>{\mathrm{K}}_{\mathrm{a}}=\frac{{\mathrm{C\alpha }}^2}{(1-\mathrm{\alpha })}$
$\left(2\right)<mspace\; width="1em"></mspace>\mathrm{Ka}<mspace\; width="1em"></mspace>=<mspace\; width="1em"></mspace>{\mathrm{C\alpha }}^2<mspace\; width="1em"></mspace>\mathrm{if}<mspace\; width="1em"></mspace>\mathrm{\alpha }\to 0$
$\left(3\right)<mspace\; width="1em"></mspace>{\mathrm{K}}_{\mathrm{a}}<mspace\; width="1em"></mspace>=<mspace\; width="1em"></mspace>\frac{{\mathrm{C\lambda }}^2}{{\mathrm{\lambda }}^2({\mathrm{\lambda }}^2-\mathrm{\lambda })}$
$\left(4\right)<mspace\; width="1em"></mspace>\mathrm{All}<mspace\; width="1em"></mspace>\mathrm{of}<mspace\; width="1em"></mspace>\mathrm{the}<mspace\; width="1em"></mspace>\mathrm{above}$