Pure Substances,mixtures,separations

Question 1

What is pure substances

Answer 1

A material that is made up of only one type of particle and has a fixed composition.

Question 2

What are mixtures

Answer 2

A combination of two or more substances

Question 3

What is the extraction of sucrose from sugar cane

Answer 3

Harvesting: Cut sugar cane stalks from fields.

Crushing: Crush stalks to extract juice containing sucrose and impurities.

Clarification: Heat juice and add lime to remove impurities; clear juice separated.

Evaporation: Boil clear juice to concentrate sugar into thick syrup.

Crystallization: Cool syrup to form sugar crystals.

Centrifuging: Spin mixture to separate sugar crystals from molasses.

Drying and Packaging: Dry sugar crystals and pack for sale.

Question 4

What are solutions

Answer 4

A homogeneous mixture where one substance (solute) is completely dissolved in another (solvent).

Question 5

What are suspensions

Answer 5

A heterogeneous mixture where particles are large enough to eventually settle out if left undisturbed.

Question 6

What are Colloids

Answer 6

A mixture where tiny particles are dispersed throughout another substance but don’t settle out.

Question 7

What are the separation techniques

Answer 7

Use filtration if you want to separate solids that don’t dissolve in liquids.

Use evaporation or distillation to separate dissolved substances.

Chromatography is good for separating mixtures of colored substances.

Magnetic separation works if one part of the mixture is magnetic.

Decantation works when liquids don’t mix or solids have settled.