Question

7.
Which of the following materials fall in the category of a "pure
substance"?
(a) Ice
(b) Milk
fet Iron
(e Hydrochloric acid
(e) Calcium oxide
(1) Mercury
Brick
(h) Wood
(i) Air.​

Answer 1

Answer:

Ice  

Iron  

Hydrochloric acid  

Calcium oxide  

Mercury

Explanation:

Pure substance is one that does not have any other substance or impurity present in it and cannot be separated into other kinds of matter by physical processes.

Answer 2

Following substance from the above mentioned list are pure substance :

$\sf\red{★Iron}$

$\sf\red{★Ice}$

$\sf\red{★Hydrochloric\:acid}$

$\sf\red{★Calcium\:oxide}$

$\sf\red{★Mercury}$