From the NCERT Chapter 2 activity with iron and sulphur, which observation correctly distinguishes the MIXTURE from the COMPOUND FeS?
A.
In the mixture, HCl added produces Hâ‚‚S gas (rotten egg smell) from sulfur. In the compound FeS, HCl produces Hâ‚‚S gas only after reacting with FeS (not separately from iron and sulfur)
B.
The mixture is black; FeS is yellow
C.
The mixture dissolves in water; FeS does not
D.
The mixture is attracted to a magnet more strongly than FeS
A. In the mixture, HCl added produces Hâ‚‚S gas (rotten egg smell) from sulfur. In the compound FeS, HCl produces Hâ‚‚S gas only after reacting with FeS (not separately from iron and sulfur)
8.
What is an 'alloy' and why is it classified as a MIXTURE and not a COMPOUND?
A.
An alloy is a heterogeneous mixture because its components are in different physical states
B.
An alloy is a homogeneous mixture of metals (or a metal with non-metals) that has variable composition — its components are not chemically bonded and retain their individual properties
C.
An alloy is an element because it contains only metallic atoms
D.
An alloy is a compound because its components are bonded in a fixed ratio
B. An alloy is a homogeneous mixture of metals (or a metal with non-metals) that has variable composition — its components are not chemically bonded and retain their individual properties
Which of the following pairs of substances, when mixed, will show the MAXIMUM separation into their original components using a simple physical method?
A.
Sugar and water (sugar dissolved in water)
B.
Sodium chloride and water (salt completely dissolved)
C.
Water and ethanol (both miscible liquids)
D.
Iron filings and sulphur powder — iron can be extracted using a magnet, sulphur can be dissolved in carbon disulphide
