Pure substance or mixture?

Question

Classify each of the following as a pure substance or mixture; if a mixture, indicate whether it is homogenous of heterogeneous: a) air b) tomato juice c) iodine crystals d) sand

Answer 1

AIR is a mixture homogeneous

TOMATO JUICE is a heterogeneous mixture

IODINE CRYSTAL is a pure substance

SAND is a heterogeneous mixture

all the best

cheers

Answer 2

a) Homogenous mixture - it's not a pure substance, being composed of nitrogen, oxygen, argon, carbon dioxide, etc. but distinct phases are not observable

b) Heterogenous mixture - it has distinct phases - a liquid phase and a solid phase.

c) Pure substance - it contains only iodine molecules and can be crystallized into a single phase.

d) Heterogenous mixture in which different minerals are clearly visible, the most abundant of which are forms of silica and silicates.

Answer 3

First, it is easy to say if something is a mixture or a pure substance. It is a little tricky to distinguish between homogenous of heterogeneous. Homogenous means something can mix well, or no layers, for example, if you open a can of campbell chicken noodle soup, you will see all the noodles and chicken chunks sank at the bottom. that will be heterogenous. If you open a can of coke, there will be no layers, and that will be homogenous.

air is roughly homogenous when close to ground level.

tomato juice, is probably with layers, so heterogenous

iodine crystals is pure iodine, so it is pure substance.

sand is obviously a mixture, and not well mixed. so heterogenous mixture (lighter particles tend to stay on the top well heavier particles are sank to the bottom.)