1. Xtra Edge February 2012 - Career Point

(a) temperature and (b) Pressure ?
Illustrate with the help of appropriate graphs.
24. Explain the following terms with suitable examples :
(i) Schottky defect, (ii) Interstitials
(iii) F-centres.
25. A first order reaction is 20% complete in 10 minutes.
Calculate (i) k of the reaction and (ii) time taken for
the reaction to go upto 75% completion.
26. (a) Name the lanthanoide element which forms
tetrapositive ions in aqueous solution.
(b) Why do Zr and Hf exhibit similar properties ?
(c) Colour of a solution of K2Cr2O7 depends on pH
of the solution. Why ?
27. (a) Write preparation of K2Cr2O7. Give reactions.
(b) Complete reactions :
K2Cr2O7 + H2SO4 + KI ⎯→
KMnO4 + H2SO4 + H2S ⎯→
28. (a) Describe the preparation of acetic acid from
acetylene.
(b) How can the following be obtained from acetic
acid
(i) Acetone
(ii)Acetaldehyde
(c) In what way can acetic acid be distinguished
from acetone ?
(d) Why do carboxylic acids not give the
characteristic reactions of a carbonyl group ?
• OR
• (a) How would you account for the following :
• (i) Aldehydes are more reactive than ketones
towards nucleophiles.
(ii) The boiling points of aldehydes and ketones
are lower than of the corresponding acids
• (iii) The aldehydes and ketones undergo a
number of addition reactions.
• (b) Give chemical tests to distinguish between :
(i) Acetaldehyde and benzaldehyde
•
•
(ii) Propanone and propanol
• 29. (a) Calculate the EMF of the cell Mg (s)/Mg 2+
(0.2 M) || Ag + (1 × 10 –3 M) / Ag ; Mg / Mg
2 Θ
E + = –
Θ
2.37 V, E +
Ag / Ag = + 0.80 V. What will be the
effect on EMF if concentration of Mg 2+ ion is
decreased to 0.1 M ?
• (b) (i) Arrange the following metals in the order in
which they displace each other from the
solution of their salts.
(ii) Given the standard electrode potentials ;
K + / K = –2.93 V, Ag + / Ag = 0.80 V,
Hg 2+ / Hg = + 0.79 V, Mg 2+ / Mg = – 2.37 V,
Cr 3+ / Cr = – 0.74 V
• Arrange these metals in their increasing order
of reducing power.
30. Arrange the following in order of the property
mentioned and give reason.
(i) F2, Cl2, Br2, I2 (Bond energy)
(ii) HCl, HF, HI, HBr (acidic strength)
(iii) PH3, NH3, SbH3, AsH3 (basic strength)
(iv) H2O, H2S, H2Se, H2Te (boiling point)
(v) HOCl, HClO2, HClO3, HClO4 (acidic strength)
MATHEMATICS
Section A
1. From the differential equation representing the
family of curves y = A cos (x + B), where A and B
are parameter.
2. Evaluate : ∫ 1 + sin x / 2 dx .
3. If →
a = iˆ
– 2 ˆj
+ 3kˆ
and →
b = kˆ î – 3 , find
| →
b × 2 →
a |.
4. If →
a = kˆ î + 2 jˆ – 3 ; →
b = 3 iˆ
– ˆj
+ 2kˆ
, show that
( →
a + →
b ) is perpendicular to ( →
a – →
b ).
5. Show that the four points whose position vectors are
6 iˆ
– 7 ˆj
, 16 iˆ
– 29 ˆj
– 4kˆ
, 3 ˆj
– 6kˆ
and
2 iˆ
+ 5 ˆj
+ 10kˆ
are coplanar.
6. Write the following function in the simplest form
tan –1 x
2 2
a – x
.
7. Find gof : If f (x) = |x| and g(x) = |5x – 2|.
8. If matrix A has order 3 × 4, matrix B has order
4 × 2 and matrix C has order 2 × 3, Find order of
(A.B.C).
9. If A =
find x.
⎡ 0
⎢
⎣ 2x
– 3
x + 2⎤
0
⎥
⎦
10. Find value of x such that
is skew symmetric,
XtraEdge for IIT-JEE 71 FEBRUARY 2012
2
5
4
1
=
2x
6
4
.
x