JEE MAIN - Chemistry (2019 - 12th January Morning Slot)
1
Two solids dissociate as follows –
The total pressure when both the solids dissociated simultaneously is -
Answer
(C)
2$$\left( {\sqrt {x + y} } \right)$$ atm
2
The major product of the following reaction is –
Answer
(A)
3
Mn2(CO)10 is an organometallic compound due to the presence of -
Answer
(D)
Mn – C bond
4
In a chemical reaction,
the initial concentration of B was 1.5 times of the
concentration of A, but the equilibrium concentrations of A and B were found to be equal. The equilibrium constant (K) for the aforesaid chemical reaction is -
Answer
(D)
4
5
The major product of the following reaction is
Answer
(D)
6
The increasing order of reactivity of the following compounds towards reaction with alkyl halides directly is
(A)
(B)
(C)
(D)
Answer
(B)
B < A < C < D
7
The standard electrode potential $${E^o }$$ and its temperature coefficient $$\left( {{{d{E^o }} \over {dT}}} \right)$$ for a cell are 2V and $$-$$ 5 $$ \times $$ 10$$-$$4 VK$$-$$1 at 300 K respectively.
The cell reaction is
Zn(s) + Cu2+ (aq) $$\buildrel \, \over
\longrightarrow $$ Zn2+ (aq) + Cu(s)
The standard reaction enthalpy ($$\Delta $$rH$${^o }$$) at 300 K in kJ mol–1 is, [Use R = 8 JK–1 mol–1 and F = 96,000C mol–1]
Answer
(A)
$$-$$ 412.8
8
Decomposition of X exhibits a rate constant of 0.05 $$\mu $$g/year. How many year are required for the decomposition of 5$$\mu $$g of X into 2.5 $$\mu $$g?
Answer
(A)
50
9
Among the following compounds most basic amino acid is -
Answer
(A)
Lysine
10
The metal d-orbitals that are directly facing the ligands in K3[Co(CN)6] are -
Answer
(A)
dx2$$-$$y2 and dz2
11
The element with Z = 120 (not yet discovered) will be an/a -
Answer
(A)
Alkaline earth metal
12
The hardness of a water sample (in terms of equivalents of CaCO3) containing 10–3 M CaSO4 is (Molar mass of CaSO4 = 136 g mol–1)
Answer
(B)
100 ppm
13
Freezing point of a 4% aqueous solution of X is equal to freezing point of 12% aqueous solution of Y. If molecular weight of X is A, then molecular weight of Y is -
Answer
(C)
3A
14
50 mL of 0.5 M oxalic acid is needed to neutralize 25 mL of sodium hydroxide solution. The amount of NaOH in 50 mL of the given sodium hydroxide solution is -
Answer
(B)
4 g
15
For diatomic ideal gas in a closed system, which of the following plots does not correctly describe the relation between various thermodynamic quantities?
Answer
(D)
16
can not be prepared by -
Answer
(D)
HCHO + PhCH(CH3)CH2MgX
17
The correct order for acid strength of compounds :
CH $$ \equiv $$ CH, CH3–C $$ \equiv $$ CH and CH2 = CH2 is as follows
Answer
(C)
HC $$ \equiv $$ CH > CH3 – C $$ \equiv $$ CH > CH2 = CH2
18
In the following reaction, products A and B are –
Answer
(B)
19
What is the work function of the metal if the light of wavelength 4000$$\mathop A\limits^ \circ $$ generates photoelectrons of velocity 6 $$ \times $$ 105 ms–1 from it ?
(Mass of electron = 9 $$ \times $$ 10–31 kg;
Velocity of light = 3 $$ \times $$ 108 ms$$-$$1 Plank's constant = 6.626 $$ \times $$ 10–34 Js;
Charge of electron = 1.6 $$ \times $$10–19 JeV–1)
Answer
(C)
2.1 eV
20
The pair of metal ions that can give a spin only magnetic moment of 3.9 BM for the complex [M(H2O)6]Cl2, is -
Answer
(B)
V2+ and Co2+
21
Among the following four aromatic compounds, which one will have the lowest melting point ?
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