JEE MAIN - Chemistry (2021 - 25th July Evening Shift)
1
In the following the correct bond order sequence is :
Answer
(C)
$$O_2^ + > {O_2} > O_2^ - > O_2^{2 - }$$
2
Which one of the following metal complexes is most stable?
Answer
(B)
[Co(en)3]Cl2
3
The ionic radii of F$$-$$ and O2$$-$$ respectively are 1.33$$\mathop A\limits^o $$ and 1.4$$\mathop A\limits^o $$, while the covalent radius of N is 0.74$$\mathop A\limits^o $$.
The correct statement for the ionic radius of N3$$-$$ from the following is :
Answer
(B)
It is bigger than O2$$-$$ and F$$-$$
4
The correct decreasing order of densities of the following compounds is :
Answer
(A)
(D) > (C) > (B) > (A)
5
Consider the above reaction, the product "P" is :
Answer
(B)
6
A reaction of benzonitrile with one equivalent CH3MgBr followed by hydrolysis produces a yellow liquid "P". The compound "P" will give positive _________.
Answer
(A)
Iodoform test
7
The spin only magnetic moments (in BM) for free Ti3+, V2+ and Sc3+ ions respectively are :
(At.No. Sc : 21, Ti : 22, V : 23)
Answer
(B)
1.73, 3.87, 0
8
Which one of the following is correct structure for cytosine?
Answer
(C)
9
Identify the species having one $$\pi$$-bond and maximum number of canonical forms from the following :
Answer
(D)
CO$$_3^{2 - }$$
10
Which one of the following metals forms interstitial hydride easily?
Consider the above reaction sequence, Product "A" and Product "B" formed respectively are :
Answer
(A)
13
What is the major product "P" of the following reaction?
Answer
(D)
14
Identify the process in which change in the oxidation state is five :
Answer
(B)
$$MnO_4^ - \to M{n^{2 + }}$$
15
Which among the following is the strongest acid ?
Answer
(D)
16
A system does 200 J of work and at the same time absorbs 150 J of heat. The magnitude of the change in internal energy is ____________ J. (Nearest integer)
Answer
50
17
An accelerated electron has a speed of 5 $$\times$$ 106 ms$$-$$1 with an uncertainty of 0.02%. The uncertainty in finding its location while in motion is x $$\times$$ 10$$-$$9 m. The value of x is ____________. (Nearest integer)
[Use mass of electron = 9.1 $$\times$$ 10$$-$$31 kg, h =6.63 $$\times$$ 10$$-$$34 Js, $$\pi$$ = 3.14]
Answer
58
18
Number of electrons present in 4f orbital of Ho3+ ion is ____________. (Given Atomic No. of Ho = 67)
Answer
10
19
Consider the above chemical reaction. The total number of stereoisomers possible for Product 'P' is _____________.
Answer
2
20
For a chemical reaction A $$\to$$ B, it was found that concentration of B is increased by 0.2 mol L$$-$$ in 30 min. The average rate of the reaction is ____________ $$\times$$ 10$$-$$1 mol L$$-$$1 h$$-$$1. (in nearest integer)
Answer
4
21
Assuming that Ba(OH)2 is completely ionised in aqueous solution under the given conditions the concentration of H3O+ ions in 0.005 M aqueous solution of Ba(OH)2 at 298 K is ______________ $$\times$$ 10$$-$$12 mol L$$-$$1. (Nearest integer)
Answer
1
22
0.8 g of an organic compound was analyzed by Kjeldahl's method for the estimation of nitrogen. If the percentage of nitrogen in the compound was found to be 42%, then ______________ mL of 1 M H2SO4 would have been neutralized by the ammonia evolved during the analysis.
Answer
12
23
When 3.00 g of a substance 'X' is dissolved in 100 g of CCl4, it raises the boiling point by 0.60 K. The molar mass of the substance 'X' is ______________ g mol$$-$$1. (Nearest integer).
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