11.

If 117 gm NaCl is dissolved in 1000 g of water the concentration of the solution is said to be :

• 2 molar

• 2 molal

• 1 normal

• 1 molal

A solution of 4.5 g of a pure non-electrolyte in 100 g of water was found to freeze at 0.465°C. The molecular weight of the solute is closest to (k_f =1.86)

• 180.0

• 135.0

• 172.0

• 90.0

The enthalpy of vaporization of substance is 840 J mol^-1 and its boiling point is -173°C. Its entropy of vaporization is :

• 42 J mol^-1 K^-1

• 21 J mol^-1 K^-1

• 84 J mol^-1 K^-1

• 8.4 J mol^-1 K^-1

Given the following thermochemical equations:

Zn + $\frac{1}{2}$O₂ → ZnO + 84,000 cal

Hg + $\frac{1}{2}$O₂ → HgO + 21,700 cal

Accordingly the heat of reaction for the following reaction, Zn + HgO → Hg + heat is:

• 105,700 cal

• 61,000 cal

• 62,300 cal

• 60,000 cal

A saturated solution of CaF₂ is 2 × 10^-4 mol/ L. Its solubility product constant is:

• 2.6 × 10^-9

• 4 × 10^-8

• 8 × 10^-12

• 3.2 × 10^-11

For the reaction,

H₂ (g) + I₂ (g) $\rightleftharpoons$ 2HI (g),

the equilibrium constants expressed in terms of concentrations K_c and in terms of partial pressures K_p, are related as:

• K_p = K_c (RT)²

• K_p = K_c(RT)^-2

• K_p = K_c

• K_c = K_p(RT)

Radioactive decay series of Uranium is denoted as:

• 4n + 1

• 4n + 2

• 4n

• 4n + 3

Which of the following pairs are correctly matched?

Select the correct answer using the codes given below-

• 1, 3 and 4

• 2, 3 and 4

• 1, 2, 3 and 4

• 1, 2 and 4

Identify the incorrect statement :

• The molarity of a solution is independent of temperature

• The tendency for catenation is much higher for carbon than for silicon

• Nitriles and iso nitriles constitute metamers

• t-butyl 1-carbocation has planar carbons and is very reactive

In one of the following reactions HNO₃ does not behave as an oxidizing agent. Identify it :

• 2HNO₃ + P₂O₅ → 2HPO₃ + N₂O₅

• I₂ + 10 HNO₃ → 2HIO₃ + 10 NO₂ + 4H₂O

• 3Cu + 8HNO₃ → 3Cu(NO₃)₂ + 2NO + 4H₂O

• NO₃ + 3Fe²⁺ + 4H⁺ → NO + 3Fe³⁺ + 2H₂O