1
WB JEE 2021
MCQ (Single Correct Answer)
+1
-0.25
Extraction of a metal (M) from its sulphide ore (M2S) involves the following chemical reactions

$$2{M_2}S + 3{O_2}\buildrel {Heat} \over \longrightarrow 2{M_2}O + 2S{O_2} \uparrow $$

$${M_2}S + 2{M_2}O\buildrel {Heat} \over \longrightarrow 6M + S{O_2} \uparrow $$

The metal (M) may be
A
Zn
B
Cu
C
Fe
D
Ca
2
WB JEE 2019
MCQ (Single Correct Answer)
+1
-0.33
In the Bayer's process, the leaching of alumina is done by using
A
Na2CO3
B
NaOH
C
SiO2
D
CaO
3
WB JEE 2019
MCQ (Single Correct Answer)
+2
-0.67
A copper coin was electroplated with Zn and then heated at high temperature until there is a change in colour. What will be the resulting colour?
A
white
B
black
C
silver
D
golden
4
WB JEE 2016
MCQ (Single Correct Answer)
+1
-0.25
The metal which can be used to obtain metallic Cu from aqueous CuSO4 solution is
A
Na
B
Ag
C
Hg
D
Fe
Questions Asked from MCQ (Single Correct Answer)
WB JEE Subjects