1
JEE Main 2023 (Online) 30th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Out of Syllabus
Change Language

In the extraction of copper, its sulphide ore is heated in a reverberatory furnace after mixing with silica to:

A
remove $$\mathrm{FeO}$$ as $$\mathrm{FeSiO}_{3}$$
B
remove calcium as $$\mathrm{CaSiO}_{3}$$
C
decrease the temperature needed for roasting of $$\mathrm{Cu}_{2} \mathrm{~S}$$
D
separate $$\mathrm{CuO}$$ as $$\mathrm{CuSiO}_{3}$$
2
JEE Main 2023 (Online) 30th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

During the qualitative analysis of $$\mathrm{SO}_{3}^{2-}$$ using dilute $$\mathrm{H}_{2} \mathrm{SO}_{4}, \mathrm{SO}_{2}$$ gas is evolved which turns $$\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}$$ solution (acidified with dilute $$\mathrm{H}_{2} \mathrm{SO}_{4}$$) :

A
blue
B
black
C
red
D
green
3
JEE Main 2023 (Online) 30th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

For $$\mathrm{OF}_{2}$$ molecule consider the following :

A. Number of lone pairs on oxygen is 2 .

B. FOF angle is less than $$104.5^{\circ}$$.

C. Oxidation state of $$\mathrm{O}$$ is $$-2$$.

D. Molecule is bent '$$\mathrm{V}$$' shaped.

E. Molecular geometry is linear.

correct options are:

A
A, C, D only
B
A, B, D only
C
C, D, E only
D
B, E, A only
4
JEE Main 2023 (Online) 30th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Match List I with List II

List I List II
A. JEE Main 2023 (Online) 30th January Morning Shift Chemistry - Haloalkanes and Haloarenes Question 38 English 1 I. Fittig reaction
B. JEE Main 2023 (Online) 30th January Morning Shift Chemistry - Haloalkanes and Haloarenes Question 38 English 2 II. Wurtz Fittig reaction
C. JEE Main 2023 (Online) 30th January Morning Shift Chemistry - Haloalkanes and Haloarenes Question 38 English 3 III. Finkelstein reaction
D. $$\mathrm{C_5H_5C1+NaI\to C_2H_5I+NaCl}$$ IV. Sandemyer reaction

Choose the correct answer from the options given below :

A
A - IV, B - II, C - III, D - I
B
A - II, B - I, C - IV, D - III
C
A - II, B - I, C - III, D - IV
D
A - III, B - II, C - IV, D - I
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