Detection of sulphur in sodium extract (Lassaigne test) is not done by which of the following reagents?

• Pb(OAc)₂

• Sodium nitroprusside

• Both Pb(OAc)₂ and Sodium nitroprusside

• Silver nitrate

Which of the following is/are incorrect representation(s) of bleaching powder?

• Ca²⁺(Cl₂O)²⁺

• Ca²⁺(ClO₂)Cl^2-

• Ca²⁺(ClO⁺)Cl^-

• All of these

The electrolyte in lead storage battery is dilute sulphuric, acid. The concentration of sulphuric acid in a lead-storage battery must be between 4.8 M and 5.3 M for most efficient functioning. A 5 mL sulphuric acid sample of a particular battery requires 50 mL of 1.0 M NaOH for complete neutralisation. Which of the following statements about the functioning of battery is the most appropriate?

• The acid concentration in the battery is not in the most effective range

• The acid concentration in the battery is in the most effective range

• The acid concentration in the battery is hardly in the most effective range

• Only a good mechanic can tell whether or not the acid concentration in the battery is in the most effective range

Which of the following statements is/are true about the P-Cl bonds in PCl₅ ?

• Three bonds are of one type and two of another type

• Two bonds are of one type and three of another type

• All the bonds are of the same type

• both (a) and (b)

In the following Haber synthesis of NH₃, the equilibrium constant for NH₃, formation, on increase in temperature, is

${\mathrm{N}}_2\left(\mathrm{g}\right)\hspace{0.17em}+ 3{\mathrm{H}}_2\left(\mathrm{g}\right) \rightleftharpoons 2{\mathrm{NH}}_3\left(\mathrm{g}\right)\hspace{0.17em}+\hspace{0.17em}\mathrm{heat}\hspace{0.17em}\mathrm{energy}$

• decreased

• increased

• first decreased and then increased

• not altered

Which one of the following represents the correct number of types of P-O bonds in P₄O₁₀?

• 1

• 2

• 3

• 4

One mole of P₄O₁₀ is allowed to react fully with dust and salt-free doubly distilled water and the volume is made up to 1L. What is the normality of the so-generated orthophosphoric acid?

P₄O₁₀ + 6H₂O → 4H₃PO₄

• 1.0 N

• 8.0 N

• 12.0 N 

• 4.0 N

Which of the following statements about the monomer and dimer of NO₂ is/are not true?

• Both are diamagnetic

• Both are paramagnetic

• The dimer is paramagnetic and the monomer is not

• all of these

39.

Given the following in Eq. (i) and (ii), calculate the EMF of the cell given in Eq. (iii)

CuI(s) + e^- → Cu(s) + I^-  E°= -0.16    ...(i)

Zn²⁺(aq) + 2e^-  →  Zn(s)  E°= -0.76  ...(ii)

Zn| Zn²⁺(1.0M) || I^-(1.0M)|CuI|Cu ... (iii)

• 1.08V

• 0.44V

• 0.92V

• 0.60V

Which of the following classes of compounds do glucose and fructose represent?

• Aldoses and ketoses, respectively

• Polyols

• Monosaccharides

• All of these