1
IIT-JEE 2008 Paper 1 Offline
MCQ (Single Correct Answer)
+3
-0

There are some deposits of nitrates and phosphates in earth's crust. Nitrates are more soluble in water. Nitrates are difficult to reduce under the laboratory conditions but microbes do it easily. Ammonia forms large number of complexes with transition metal ions. Hybridisation easily explains the ease of sigma donation capability of NH$$_3$$ and PH$$_3$$. Phosphine is a flammable gas and is prepared from white phosphorus.

Among the following, the correct statement is :

A
Between NH$$_3$$ and PH$$_3$$, NH$$_3$$ is better electron donor because the lone pair of electrons occupies spherical 's' orbital and is less directional.
B
Between NH$$_3$$ and PH$$_3$$, PH$$_3$$ is a better electron donor because the lone pair of electrons occupies sp$$^3$$ orbital and is more directional.
C
Between NH$$_3$$ and PH$$_3$$, NH$$_3$$ is a better electron donor because the lone pair of electrons occupies sp$$^3$$ orbital and is more directional.
D
Between NH$$_3$$ and PH$$_3$$, PH$$_3$$ is better electron donor because the lone pair of electrons occupies spherical 's' orbital and is less directional.
2
IIT-JEE 2008 Paper 1 Offline
MCQ (Single Correct Answer)
+3
-0

There are some deposits of nitrates and phosphates in earth's crust. Nitrates are more soluble in water. Nitrates are difficult to reduce under the laboratory conditions but microbes do it easily. Ammonia forms large number of complexes with transition metal ions. Hybridisation easily explains the ease of sigma donation capability of NH$$_3$$ and PH$$_3$$. Phosphine is a flammable gas and is prepared from white phosphorus.

White phosphorus on reaction with NaOH gives PH$$_3$$ as one of the products. This is a:

A
dimerisation reaction
B
disproportionation reaction
C
condensation reaction
D
precipitation reaction
3
IIT-JEE 2007 Paper 2 Offline
MCQ (Single Correct Answer)
+3
-1
This question contains STATEMENT-1 (Assertion) and STATEMENT-2 (Reason) and has 4 choices (a), (b), (c), (d) out of which ONLY ONE is correct.

STATEMENT-1 : Band gap in germanium is small. because

STATEMENT-2 : The energy gap of each germanium atomic energy level is infinitesimally small.
A
Statement - 1 is True, Statement - 2 is True; Statement - 2 is a correct explanation for Statement - 1
B
Statement - 1 is True, Statement - 2 is True; Statement - 2 is not a correct explanation for Statement - 1
C
Statement - 1 is True, Statement - 2 is False
D
Statement - 1 is False, Statement - 2 is True
4
IIT-JEE 1999
MCQ (Single Correct Answer)
+2
-0.5
The oxidation number of sulphur in S8,S2F2,H2S respectively, are
A
0, +1 and -2
B
+2, +1 and -2
C
0, +1 and +2
D
-2, +1 and -2
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