## Chemistry (25) Full Length

### PHYSICS

##### Q 1.

The mechanism of $$S_N1$$ reaction is given as:

A student writes general characteristics based on the given mechanism as :

(a) The reaction is favoured by weak nucleophiles.            (b) $$R^+$$ would be easily formed if the substituents are bulky

(c) The reaction is accompanied by recemization              (d) The reaction i`s favoured by non-polar solvents.

Which observations are correct ?

##### Q 2.

The figure that is not a direct manifestation of the quantum nature of atom is :

##### Q 3.

The incorrect statement(s) among (a) – (b) regarding acid rain is (are):

(a) It can corrode water pipes

(b) It can damage structures made up of stone.

(c) It cannot cause respiratory ailments in animals

(d) It is not harmful for trees

##### Q 4.
For the reaction $$2A+3B+{3\over2}C\rightarrow3P$$, which statement is correct?

##### Q 5.
Which one of the following graphs is not correct for ideal gas ?

##### Q 6.
The atomic number of the element unnilennium is :

##### Q 7.
The five successive ionization enthalpies of an element are 800, 2427, 3658, 35024 and 32824 kJ $$mol^{-1}$$ . The number of valence electrons in the element is:

##### Q 9.
Thermal power plants can lead to :

##### Q 10.
The increasing order of the reactivity of the following compounds in nucleophile addition reaction is: Propanal, Benzaldehyde, Propanone, Butanone

##### Q 11.
On heating compound (A) gives a gas (B) which is a constituent of air. This gas when treated with $$H_2$$ in the presence of a catalyst gives another gas (C) which is basic in nature. (A) should not be :

##### Q 12.
In a molecule of pyrophosphoric acid, the number of P – OH, P = 0 and P – O – P bonds/moiety(ies) respectively are :

##### Q 13.
100 mL of 0.1 M HCl is taken in a beaker and to it 100 mL of 0.1 M NaOH is added in steps of 2 mL and the pH is continuously measured. Which of the following graphs correctly depicts the change in pH?

##### Q 14.
Which of the following compounds will show retention in configuration on nucleophile substitution by OH– ion ?

##### Q 15.
Let $$C_{naCl}$$ and $$C_{BaSO_4}$$ be the conductances (in S) measured for saturated aqueous solutions of $$NaCl$$ and $$BaSO_4$$ respectively, at a temperature T. Which of the following is false?

##### Q 16.

The decreasing order of reactivity of the following compounds towards nucleophilic substitution $$S_N2$$ is:

##### Q 18.
An acidic buffer is obtained on mixing :

##### Q 19.

The strengths of 5.6 volume hydrogen peroxide (of density 1 g/mL) in terms of mass percentage and molarity (M) respectively, are: (Take molar mass of hydrogen peroxide as 34 g/mol)                                                                                (Take molar mass of hydrogen peroxide as 34 g/mol)

##### Q 20.
In Carius method of estimation of halogen, 0.172 g of an organic compound showed presence of 0.08 g of bromine. Which of these is the correct structure of the compound ?

##### Q 21.

The mass of gas adsorbed, $$X$$, per unit mass of adsorbate, $$m$$, was measured at various pressures, p. A graph between $$log{x\over m}$$and log p gives a straight line with slope equal to 2 and the intercept equal to 0.4771. The value of $$\frac x m$$ at a pressure of 4 atm is :                                                                                  (Given log 3 = 0.4771)

##### Q 22.

The total number of monohalogenated organic products in the following (including stereoisomers) reaction is__________.

##### Q 23.
An acidic solution of dichromate is electrolyzed for 8 minutes using 2A current. As per the following equation $$Cr^2O_7^2+14\;H^++6e^-\rightarrow2C^{3+}+7H_2O$$ The amount of Cr3+ obtained was 0.104 g. The efficiency of the process (in%) is (Take : F = 960000 C, At. mass of chromium = 52)
##### Q 24.
The internal energy change (in J) when 90 g of water undergoes complete evaporation at 100ºC is…………… (Given :$$\Delta H_{vap}\;for \;water\;at\ 373\;K=41kJ/mol,\ R\ =8.314\ JK^{-1}mol^{-1}$$ )
##### Q 25.
The mole fraction of glucose $$(C_6H_{12}O_6)$$ in an aqueous binary solution is $$0.1$$. The mass percentage of water in it, to the nearest integer, is ………