Question

part 1: types of mixtures

1. define mixture:
2. circle the correct answer:

o saltwater is a (homogeneous / heterogeneous) mixture.
o a salad is a (homogeneous / heterogeneous) mixture.

1. fill in the chart:

example	homogeneous or heterogeneous?	why?
pizza
milk
trail mix

draw a simple sketch of a homogeneous mixture and a heterogeneous mixture. label them.
separating mixtures
match the separation method with the correct description:

separation method	description
evaporation	b) using magnets to separate magnetic substances
distillation	c) using filter paper to separate solid from liquid
magnetic separation	d) using differences in boiling points to separate liquids

no questions:
how would you separate salt from water?
how would you separate sand from iron filings?
how would you separate alcohol from water?

Explanation:

1. A mixture is a combination of two or more substances that are not chemically combined.
2. Saltwater is a homogeneous mixture because the salt is evenly dissolved in the water. A salad is a heterogeneous mixture as you can see the different components like vegetables, dressings etc. separately.
3. Air is a homogeneous mixture as its components like nitrogen, oxygen etc. are uniformly distributed. Pizza is a heterogeneous mixture as you can see different toppings, crust etc. separately. Milk is a homogeneous mixture (colloid) as it appears uniform. Trail Mix is a heterogeneous mixture as you can see different nuts, raisins etc. separately.

Filtration uses filter - paper to separate solid from liquid. Evaporation uses heat to remove solvent and leave solute behind. Distillation uses differences in boiling points to separate liquids. Magnetic separation uses magnets to separate magnetic substances. To separate salt from water, evaporation is used as heating water makes it evaporate leaving salt behind. To separate sand from iron filings, magnetic separation is used as iron is magnetic and sand is not. To separate alcohol from water, distillation is used as they have different boiling points.

Answer:

1. A combination of two or more substances that are not chemically combined.
2. Saltwater: homogeneous; Salad: heterogeneous
3. Air: homogeneous, components uniformly distributed; Pizza: heterogeneous, different parts visible; Milk: homogeneous, appears uniform; Trail Mix: heterogeneous, different components visible

Filtration - c; Evaporation - a; Distillation - d; Magnetic Separation - b
How to separate salt from water: Evaporation
How to separate sand from iron filings: Magnetic Separation
How to separate alcohol from water: Distillation