JEE MAIN - Chemistry (2020 - 7th January Morning Slot)
1
Two solutions, A and B, each of 100L was made by dissolving 4g of NaOH and 9.8 g of H2SO4 in water, respectively. The pH of the resultant solution obtained from mixing 40L of solution A and 10L of solution B is :
Answer
10.6
2
Chlorine reacts with hot and concentrated NaOH and produces compounds (X) and (Y). Compound
(X) gives white precipitate with silver nitrate solution. The average bond order between CI and O
atoms in (Y) is.
Answer
1.66to1.67
3
For the reaction :
A($$l$$) $$ \to $$ 2B(g)
$$\Delta U = 2.1\,kcal,\,\Delta S = 20\,cal\,{K^{ - 1}}$$ at 300 K
Hence $$\Delta $$G in kcal is :
Answer
-2.7
4
During the nuclear explosion, one of the products is 90Sr with half life of 6.93 years. If 1 $$\mu $$ g of 90Sr was absorbed in the bones of newly born baby in placed of Ca, how much time, in years, is required to reduce much time, in year, is required to reduce it by 90% if it not lost metabolically.
Answer
23to23.03
5
The number of orbitals associated with quantum number n = 5, ms = +$${1 \over 2}$$ is :
Answer
(B)
25
6
What is the product of following reaction ?
Answer
(B)
7
Consider the following reaction :
The product 'X' is used :
Answer
(B)
in acid base titration as an indicatior.
8
Given that the standard potentials (Eo) of Cu2+/Cu and Cu+/Cu are 0.34 V and 0.522 V respectively, the Eo of Cu2+/Cu+ :
1- methyl ethylene oxide when treated with an excess of HBr produces :
Answer
(A)
16
The electron gain enthalpy (in KJ/mol) of fluorine, chlorine, bromine and iodine, respectively are:
Answer
(C)
-333, -349, -325 and -296
17
A solution of m-chloronailimne, m-chlorophenol and m-chlorobenzoic acid in ethyal acetate was extracted initially with a saturated solution of NaHCO3
to give fraction A. The left over organic phase
was extracted with dilute NaoH solution tio give fraction B. The final organiic layer was labelled as
fraction C. Fractions A,B and C, contain respectively :
Answer
(B)
m-chlorobenzoic acid, m-chlorophenol and m-chloroaniline.
18
The increasing order to Pkb for the following compounds will be :
Answer
(C)
(B) < (A) < (C)
19
At 35oC, the vapour pressure of CS2
is 512 mm. Hg and that of acetone is 344 mm Hg. A solution
of CS2
in acetone has a total vapour pressure of 600 mm Hg. The false statement amongst the
following is :
Answer
(B)
a mixture of 100 ml. CS2 and 100 ml. acetone has a volume < 200 ml.
20
Oxidation number of potassium in K2O. K2O2 and KO2 respectively is :
Answer
(B)
+1, +1 and + 1
21
The theory that can completely/properly explain the nature of bonding in [Ni(Co)4] is :