1
JEE Main 2023 (Online) 25th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Out of Syllabus
Change Language

Which one of the following reactions does not occur during extraction of copper?

A
$$\mathrm{2FeS + 3{O_2} \to 2FeO + 2S{O_2}}$$
B
$$\mathrm{FeO + Si{O_2} \to FeSi{O_3}}$$
C
$$\mathrm{CaO + Si{O_2} \to CaSi{O_3}}$$
D
$$\mathrm{2C{u_2}s + 3{O_2} \to 2C{u_2}O + 2S{O_2}}$$
2
JEE Main 2023 (Online) 25th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Match items of Row I with those of Row II.

Row I :

JEE Main 2023 (Online) 25th January Morning Shift Chemistry - Biomolecules Question 35 English

Row II :

(i) $$\alpha$$-$$\mathrm{D}$$-$$(-)$$-$$\mathrm{Fructofuranose}$$

(ii) $$\beta$$-D-$$(-)$$-Fructofuranose

(iii) $$\alpha$$-D-$$(-)$$ Glucopyranose

(iv) $$\beta$$-D-$$(-)$$-Glucopyranose

Correct match is

A
A $$\to$$ iii, B $$\to$$ iv, C $$\to$$ i, D $$\to$$ ii
B
A $$\to$$ iv, B $$\to$$ iii, C $$\to$$ i, D $$\to$$ ii
C
A $$\to$$ i, B $$\to$$ ii, C $$\to$$ iii, D $$\to$$ iv
D
A $$\to$$ iii, B $$\to$$ iv, C $$\to$$ ii, D $$\to$$ i
3
JEE Main 2023 (Online) 25th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Out of Syllabus
Change Language

Which of the following statements is incorrect for antibiotics?

A
An antibiotic should promote the growth or survival of microorganisms.
B
An antibiotic must be a product of metabolism.
C
An antibiotic should be effective in low concentrations.
D
An antibiotic is a synthetic substance produced as a structural analogue of naturally occurring antibiotic.
4
JEE Main 2023 (Online) 25th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

The compound which will have the lowest rate towards nucleophilic aromatic substitution on treatment with OH$$^-$$ is

A
JEE Main 2023 (Online) 25th January Morning Shift Chemistry - Haloalkanes and Haloarenes Question 38 English Option 1
B
JEE Main 2023 (Online) 25th January Morning Shift Chemistry - Haloalkanes and Haloarenes Question 38 English Option 2
C
JEE Main 2023 (Online) 25th January Morning Shift Chemistry - Haloalkanes and Haloarenes Question 38 English Option 3
D
JEE Main 2023 (Online) 25th January Morning Shift Chemistry - Haloalkanes and Haloarenes Question 38 English Option 4
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