JEE Main 2021 (Online) 22th July Evening Shift | Isolation of Elements Question 52 | Chemistry

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JEE Main 2021 (Online) 22th July Evening Shift

MCQ (Single Correct Answer)

-1

Sulphide ion is soft base and its ores are common for metals.

(a) Pb (b) Al (c) Ag (d) Mg

(a) and (c) only

(a) and (d) only

(a) and (b) only

JEE Main 2021 (Online) 20th July Evening Shift

MCQ (Single Correct Answer)

-1

Consider two chemical reactions (A) and (B) that take place during metallurgical process:

(A) $$ZnC{O_{3(s)}}\buildrel \Delta \over \longrightarrow Zn{O_{(s)}} + C{O_{2(g)}}$$

(B) $$2Zn{S_{(s)}} + 3{O_{2(g)}}\buildrel \Delta \over \longrightarrow 2Zn{O_{(s)}} + 2S{O_{2(g)}}$$

The correct option of names given to them respectively is :

(A) is calcination and (B) is roasting

Both (A) and (B) are producing same product so both are roasting

Both (A) and (B) are producing same product so both are calcination

(A) is roasting and (B) is calcination

JEE Main 2021 (Online) 20th July Morning Shift

MCQ (Single Correct Answer)

-1

Given below are two statements. One is labelled as Assertion A nd the other is labelled as Reason R.

Assertion A : Sharp glass edge becomes smooth on heating it upto its melting point.

Reason R : The viscosity of glass decreases on melting.

Choose the most appropriate answer from the options given below.

A is true but R is false

Both A and R are true but R is NOT the correct explanation of A.

A is false but R is true.

Both A and R are true and R is the correct explanation of A.

JEE Main 2021 (Online) 20th July Morning Shift

MCQ (Single Correct Answer)

-1

An inorganic Compound 'X' on treatment with concentrated H₂SO₄ produces brown fumes and gives dark brown ring with FeSO₄ in presence of concentrated H₂SO₄. Also Compound 'X' gives precipitate 'Y', when its solution in dilute HCl is treated with H₂S gas. The precipitate 'Y' on treatment with concentrated HNO₃ followed by excess of NH₄OH further gives deep blue coloured solution, Compound 'X' is :

Co(NO₃)₂

Pb(NO₂)₂

Cu(NO₃)₂

Pb(NO₃)₂

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