31.

In the presence of a catalyst, the heat evolved or absorbed during the reaction

• increases

• decreases

• remains unchanged

• may increase or decrease

The average kinetic energy of an ideal gas per molecule in SI units at 25°C will be

• 6.17 x 10^-21 JK^-1

• 6.17 x 10^-21 JK^-1

• 6.17 x 10²⁰ JK^-1

• 7.16 x 10^-20 JK^-1

Which one of the following acts as a nucleophile?

• (CH₃)₃N

• BF₃

• $\stackrel{+}{\mathrm{N}}$O₂

• ${\mathrm{CH}}_3 - \stackrel{+}{\mathrm{C}} = \mathrm{O}$

Which of the following compounds have highest melting point?

• Only I

• Only II

• I and II

• II and III

Identify the major product 'X' obtained in the following reaction.

2, 3-dimethyl butan-2-ol $\stackrel{\mathrm{conc}. {\mathrm{H}}_2{\mathrm{SO}}_4}{\to }$ X

Addition ofwater to alkynes occurs in acidic medium and in the presence of Hg²⁺ ions as a catalyst. Which of the following products will be formed on addition of water to but-1-yne under these conditions?

• CH₃CH₂CH₂CHO

• CH₃CH₂COCH₃

• CH₃CH₂COOH

• CH₃COOH + HCHO

The correct order of increasing acidic strength is

• phenol < ethanol < chloroacetic acid < acetic acid

• ethanol < phenol < chloroacetic acid < acetic acid

• ethanol < phenol < acetic acid < chloroacetic acid

• chloroacetic acid < acetic acid < phenol < ethanol

Which of the following is 3° amine?

• 1-methylcyclohexylamine

• Triethyl amine

• Tert-butylamine

• N-methyl aniline

Which of the following enhances lathering property ofsoap?

• Sodium carbonate

• Sodium rosinate

• Sodiume stearate

• Trisodium phosphate

The deficiency of vitamin C causes

• scurvy

• rickets

• pyrrohea

• pernicious anaemia