NEET TEST SERIES 134 CHEMISTRY

1. Which of the following pair make fastest coupling reaction in acidic medium?

 

2. Which of the following statements about the composition of the vapour over an ideal 1: 1 molar mixture of benzene and toluene is correct? Assume that the temperature is constant at 25°C [Given, vapour pressure data at 25°C, benzene = 12.8kPa , toluene = 3.85 kPa]

a) The vapour will contain equal amounts of benzene and toluene.
b) Not enough information is given to make a prediction.
c) The vapour will contain a higher percentage of benzene.
d) The vapour will contain a higher percentage of toluene.

3. Compound A, C₈H₁₀O is found to react with NaOI (produced by reacting Y with NaOH) and yields a yellow precipitate with characteristic smell. A and Y are respectively.

5. The correct difference between first and second order reactions is that:

a) A first-order reaction can be catalyzed; a second-order reaction cannot be catalyzed.

b) The half-life of a first-order reaction does not depend on [A]₀; the half-life of a second-order reaction does depend on [A]₀.

c) The rate of a first-order reaction does not depend on reactant concentrations; the rate of a second-order reaction does depend on reactant concentrations.

d) The rate of a first-order reaction does depend on reactant concentrations; the rate of a second-order reaction does not depend on reactant concentrations.

6. Predict the correct intermediate and product in the following reaction.

Intermediate ————>  Product
           (A)                               (B)

7. The bond dissociation energies of , and XY are in the ratio of 1: 0.5: 1. AH for the formation of XY is 200 kJ mol^-1. The bond dissociation energy of X₂ will be:

(a) 200 kJ mol^-1
(b) 100 kJ mol^-1
(c) 800 kJ mol^-1
(d) 400 kJ mol^-1

8. The temperature at which the given reaction is at equilibrium
Ag₂ O(s) → 2Ag(s) + (1/2) O₂ (g)
∆H = 30.5 kJ and AS = 0.066 kJ mol^-1

(a) 462.12 K
(b) 362.12 K
(c) 262.12 K
(d) 562.12 K

9. Carboxylic acids have higher boiling points than aldehydes, ketones and even alcohols of comparable molecular mass. It is due to their:

a) More extensive association of carboxylic acid via van der Waals force of attraction.
b) Formation of carboxylate ion.
c) Formation of intramolecular H-bonding.
d) Formation of intermolecular H-bonding

10. The measurement of the electron position is associated with an uncertainty in momentum, which is equal to 1 × 10^-18 g cm s^-1. The uncertainty in electron velocity is:
[mass of an electron is 9 × 10^-28 g ]

a) 1 × 10⁹ cm s^-1
b) 1 × 10⁶ cm s^-1
c) 1 × 10⁵ cm s^-1
d) 1 × 10¹¹ cm s^-1

11. The number of structural isomers possible from the molecular formula C₃H₉N is:

(a) 4
(b) 5
(c) 2
(d) 3

15. 0 g of magnesium is burnt with 0.56 g of oxygen in a closed vessel. Which reactant is left in excess and how much? [At. weight of Mg = 24, O = 16

(a) Mg, 0.16 g

(b) O₂, 0.16 g

(c) Mg, 0.44 g

(d) O₂ , 0.28 g

16. In the reaction with HCl, an alkene reacts in accordance with the Markovnikov’s rule to give a product 1-chloro-1 methyl cyclohexane. The possible alkene is

17. Which of the following has longest C-O bond length?
[Free C-O bond length in CO is 1.128 Å].

(a) [Fe(CO)₄]^2-
(b) [Mn(CO)₆]⁺
(c) Ni(CO)₄
(d) [Co(CO)₄]^–

18. Amongst the elements with following electronic configurations, which one may have the highest ionization energy?

(a) [Ne] 3s², 3p³
(b) [Ne] 3s², 3p²
(c) [Ar] 3d¹⁰, 4s², 4p³
(d) [Ne] 3s², 3p¹

19. In a set of reactions acetic acid yielded a product D.

The structure of D would be

20. In a set of reaction,ethyl benzene yields a product D.