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# NEET Chemistry Solved Question Paper 2009

#### Multiple Choice Questions

1.

Which of the following is correct?

• The pH of one litre solution containing 0.49 g of H2SO4 is 2.0

• The conjugate base of H2S is S2-

• BF3 is a Lewis base

• Phenolphthalein is colourless in basic medium

A.

The pH of one litre solution containing 0.49 g of H2SO4 is 2.0

w = 0.49 gm

E = 49

V = 1000 mL

2.

What is the wavelength (in m) of a particle of mass 6.62 x 10-29 g moving with a velocity of 103 ms-1?

• 6.62 x 10-4

• 6.62 x 10-3

• 10-5

• 105

C.

10-5

According to de-Broglie equation

3.

What is the equation for the equilibrium constant (Kc) for the following reaction?

C.

Equilibrium constant, Kc

Kc$\frac{{\left[\mathrm{C}\right]}^{2}{3}}}{{\left[\mathrm{A}\right]}^{1}{2}}{\left[\mathrm{B}\right]}^{1}{3}}}$

4.

The total number of orbitals in the fifth energy level is

• 5

• 10

• 18

• 25

D.

25

The total number of atomic orbitals (total m) in nth shell is equal to n2.

So, in the fifth shell = 52 = 25

5.

A 0.5 g/L solution of glucose is found to be isotonic with a 2.5 g/L solution of an organic compound. What will be the molecular weight of that organic compound ?

• 300

• 600

• 900

• 200

C.

900

Molarity of glucose solution =  = 0.00277 M

Isotonic solution have equal molar concentrations, hence molarity of organic compound solution= 0.00277 M

$\therefore$ Molecular weight of compound =  = 900

Therefore, the molecular weight of the given organic compound is 900.

6.

H-O-H bond angle in H2O is 104.5° and not 109° 28' because of

• lone pair-lone pair repulsion

• lone pair-bond pair repulsion

• bond pair-bond pair repulsion

• high electronegativity of oxygen

A.

lone pair-lone pair repulsion

The hybridisation of oxygen in water molecule is sp3. So, water molecule must be tetrahedral and have bond angle 109°28'. But because of the presence of two lone pair of electrons on oxygen atom (repulsion between lone pair-lone pair) the bond angle decreases about 104.5° and the geometry becomes distorted tertrahedral or V-shaped.

7.

The heat of formation of CO(g) and CO2 (g)are $∆$H = -110 and $∆$H = - 393 kJ mol-1 respectively. What is the heat of reaction ($∆$H) (in kJ mol-1) for the following reaction?

CO (g) + $\frac{1}{2}{\mathrm{O}}^{2}$ (g) $\to$ CO2(g)

• -504

• -142.5

• -283

• 504

C.

-283

8.

A 0.1 aqueous solution of a weak acid is 2% ionised. If the ionic product of water is 1 x 10-4, the [OH-] is

• 5 x 10-12 M

• 2 x 10-3 M

• 1 x 10-14 M

• None of these

A.

5 x 10-12 M

Since, it is a weak acid, the equation to calculate [H+] is

= C x $\mathrm{\alpha }$ ($\mathrm{\alpha }$ = % of ionisation)

= 0.1 x 0.02 = 2 x 10-3 M

Kw = [H+][OH-]

[OH-] =

= 5 x 10-12 M

9.

Which of the following is correct ?

• Catalyst undergoes permanent chemical change

• Particle size of solute in true solution is 10-3 m

• Starch solution is a hydrosol

• Hydrolysis of liquid ester in the presence of mineral acid is an example of heterogeneous catalysis reactions

C.

Starch solution is a hydrosol

Starch solution is a hydrosol as it forms colloidal solution with water.

10.

Which of the following is not correct ?

• Hydrolysis of NCl3 gives NH3 and HOCl

• NH3 is less stable than PH3

• NH3 is a weak reducing reagent compared to PH3

• Nitric oxide in solid state exhibits diamagnetic property

B.

NH3 is less stable than PH3

Among V A group hydrides, the stability decreases in going down the group i.e.,

NH3 > PH3 > AsH3 > SbH3 > BiH3

It is due to the increasing bond length down the group.