For preparing 3.00 L of 1M NaOH by mixing portions of two stock solutions (A and B) of 2.50 M NaOH and 0.40 M NaOH respectively. Find out the amount of B stock solution (in L) added.

• 8.57 L

• 2.14 L

• 1.28 L

• 7.51 L

The Vividh Bharti Station of All India Radio, Delhi, broadcasts on a frequency of 1,368 kHz (Kilohertz). Calculate the wavelength ($\mathrm{\lambda }$) of the electromagnetic radiation emitted by transmitter. Which part of the electromagnetic spectrum does it belong to?

• 319.4 m and X-rays

• 319.4 m and radiowave

• 219.3 m and microwave

• 219.3 m and radiowave

In an atom, an electron is moving with a speed of 600 m/s with an accuracy of 0.005%. Certainty with which the position of the electron can be located is

(Given, h= 6.6 x 10^-34 kg m² s^-1, mass of electron e_m = 9.1 x 10^-31 kg)

• 215 x 10^-3 m

• 2.78 x 10^-3 m

• 1.92 x 10^-3 m

• 3.24 x 10^-3 m

4.

What would be the heat released when an aqueous solution containing 0.5 mole of HNO₃ is mixed with 0.3 mole of OH^-?  (enthalpy of neutralisation is- 57.1 kJ)

• 28.5 kJ

• 17.1 kJ

• 45.7 kJ

• 1.7 kJ

The number average molar mass and mass average molar mass of a polymer are respectively 30,000 and 40,000. The
polydispersity index (PDI) of the polymer is 

• -1

• 0

• > 1

• < 1

The charge/size ratio of a cation determines its polarising power. Which one of the following sequences represents the increasing order of the polarising power of the cationic species, K⁺, Ca²⁺, Mg²⁺, Be²⁺?

• K⁺ < Ca²⁺ < Mg²⁺ < Be²⁺

• Be²⁺ < K²⁺ < Ca²⁺ < Mg²⁺

• Mg²⁺< Be²⁺ < K⁺ < Ca²⁺

• Ca²⁺ < Mg²⁺ < Be⁺ < K⁺

In an amino acid, the carboxyl group ionises at pK_a = 2.34 and ammonium ion at pK_a2 = 9.60. The isoelectric point of the amino acid is at pH

• 4.32

• 3.34

• 9.46

• 5.97

0.40 g of helium in a bulb at a temperature of T K had a pressure of p atm. When the bulb was immersed in water bath at temperature 50 K more than the first one, 0.08 g of gas had to be removed to restore the original pressure. T is

• 500 K

• 400 K

• 600 K

• 200 K

What percentage of $\mathrm{\beta }$-D-(+-glucopyranose is found at equilibrium in the aqueous solution?

• 64%

• 36%

• $\approx$100%

• $\approx$50%

Which of the following is correctly arranged in order of increasing weight?

• 0.0105 equivalent of H₂CO₂ ·2H₂O < 0.625 g of Fe < 0.006 g atom of Ag <6.0 x 10²¹ atoms of Zn

• 0.625 g of Fe < 0.0105 equivalent of H₂C₂O₄ ·2H₂O < 6.0 x 10²¹ atoms of Zn < 0.006 g atom of Ag 

• 0.625 g of Fe < 6.0 x 10²¹ atoms of Zn < 0.006 g atom of Ag < 0.0105 equivalent of H₂C₂O₄ ·2H₂O

• 0.0105 equivalent of H₂C₂O₄. 2H2O < 0.006 g atom of Ag <6.0 x 10²¹ atoms of Zn < 0.625 g of Fe