A litre solution containing NH₄Cl and NH₄OH has hydroxide ion concentration of 10^-6 mol L^-1. Which of the following hydroxide could be precipitated when the solution is added to 1L solution of 0.1M metal ions?

Ba(OH)₂ (Ksp = 5 x 10^-3)

Ni(OH)₂ (K_sp = 1.6 x 10^-16)

Mn(OH)₂ (K_sp = 2 x 10^-13) 

Fe(OH)₂ (K_sp = 8 x 10^-16)

• I and IV

• III and IV

• II and IV

• II , III and IV

Forty millilitre of CO was mixed 100 mL of O₂ and the mixture was exploded. On cooling, the reaction mixture was shaken with KOH. What volume of gas is left?

• 80 ml of O₂

• 60 ml of O₂

• 80 ml of CO₂

• 50 ml of CO₂

Consider the following pairs of ions:

I. Sc³⁺ and Ti⁴⁺        II. Mn²⁺ and Fe²⁺

III. Fe²⁺ and Co³⁺    IV. Cu⁺ and Zn²⁺

Among these pairs ofions, isoelectronic pairs would include:

• II, III and IV

• I, III and IV

• I, II and IV

• I, II and III

The decreasing nucleophilicity of the following is:

I. CH₃S^-              II. CH₃O^-

III. ^-OH               IV. EtO^-

• II > III > 1V > I

• III > IV > I > II

• IV > III > I > II

• II < I < IV < III

Arrange the following (I to IV) in the order of increasing masses:

I. 0.5 mole of O₃

II. 0.5 g atom of oxygen

III. 3.011 x 10²³ mlecules of O₂

IV. 5.6 l of CO₂ at STP

• II < IV < III < I

• IV < III < I < II

• II < I < IV < III

• I < II < III < IV

6.

The number of σ bonds in P₄O₁₀ is:

• 6

• 16

• 7

• 17

One mole of FeC₂O₄ is oxidised by x moles of Cr₂${\mathrm{O}}_7^{2-}$ in acidic medium , x is:

• 0.5

• 1.0

• 1.5

• 2.0

10 moles of ideal gas expand isothermally and reversibly from a pressure of 10 atrn to 1 atm at 300K. What is the largest mass which can lifted through a height of 100 meter?

• 48.75 kg

• 58.55 kg

• 75.64 kg

• 64.13 kg

For a chemical reaction, temperature is raised from 25° C to 35° C. The value of equilibrium constant, K_p is doubled . The heat of reaction ($\mathrm{\Delta }$H) for the reaction will be :

• 13.834 kcal

• 11.714 kcal

• 10.726 kcal

• 4.312 kcal

4.0 g molecular PCl₅ were heated in a vessel of 6 L volume. At equilibrium state , 50% of PCl₅ is dissociated. The equilibrium constant for the reaction is :

• 0.66 mol L^-1

• 0.33 mol L^-1

• 0.44 mol L^-1

• 0.88 mol L^-1