NEET Chemistry Solved Question Paper 2006

For an endothermic reactions $∆\mathrm{H}$ is positive because in endothermic reaction heat is always absorbed.

The proton has unit positive charge (+1.602 × 10^-19 Coulombs) and its mass is 1.007 amu, i.e. 1.677 × 10^-27 kg).

We know,

1 gm equivalent weight of NaOH = 40 gm

$\therefore$                     40 gm of NaOH = 1 gm eq. of NaOH

$\therefore$                0.275 gm of NaOH = $\frac{1}{40}$× 0.275 

                                               = $\frac{1}{40}$× 0.274 × 1000

                                               = 6.88 m eq.

$\therefore$                                    $\underset{\left(\mathrm{HCl}\right)}{{\mathrm{N}}_1{\mathrm{V}}_1} = \underset{\left(\mathrm{NaOH}\right)}{{\mathrm{N}}_2{\mathrm{V}}_2}$

                                N₁ × 35.4 = 6.88 ($\because$meq = NV)

                                           ${\mathrm{N}}_1 = 0.194$

The correct sequence of hybridisation of methane, ethene and ethyne is sp³, sp² and sp.

AgCl is insoluble in water because the forces favouring the formation of silver hydroxide are too weak to break the ionic bonds between silver and chlorine.

Buffer's solutions are the solutions which resists the chnages in its pH value on addition of small amount of a base or an acid. 

Among all the given options, CH₃COOH and CH₃COONa are the example of Buffer's solutions because they are the combination of weak acid and salt of strong base.

Among all the given options, CHCl₃ molecule has largest dipole moment.

amu is represented by atomic mass unit. It is used in place of unified mass unit.

1 amu = 1 avogram = 1 aston = 1 dalton

1 amu = $\frac{1}{12}$ × mass of C-12 atom

          = $\frac{1}{12}$ × 1.9924 × 10^-23 gm

          = 1.66 × 10^-24 gm

          = 1.66 × 10^-27 kg

We know,

m = $\frac{1000 {\mathrm{K}}_{\mathrm{f}} \times \mathrm{w}}{∆\mathrm{TW}}$

Here, $∆\mathrm{T}$ = 1.2°C; K_f = 1.85°

           w = 5 gm;  W = 50 gm

$\therefore$ m = $\frac{1000 \times 1.85 \times 5}{1.2 \times 50}$ = 154.2

154.2 is the molecular weight of a substance.

The radius of hydrogen atom = 0.53 Å.

₃Li⁺² ion consists of only 1 electron but it has 3 protons in its nucleus. Hence, its electron fall is three times more attracted from nucleus as compared to hydrogen atom. Thus, the radius of ₃Li⁺² is = $\frac{0.53}{3}$ = 0.17 Å