Chemistry2.2
Slide
1 of 21
2.2
Mixtures
Panning is one way to separate
gold from a mixture of gold and
materials such as sand or gravel.
A pan containing the mixture is
place underwater and shaken
vigorously from left to right. You
will learn how to classify and
separate mixtures.
Slide
2 of 21
© Copyright Pearson Prentice Hall
2.2
Mixtures
>
Classifying Mixtures
Classifying Mixtures
How can mixtures be classified?
Slide
3 of 21
© Copyright Pearson Prentice Hall
2.2
Mixtures
>
Classifying Mixtures
A mixture is a physical blend of two or more
components.
A salad bar provides a range of items. Customers
choose how much of each item to use in their
salads. Each salad has a different composition.
Slide
4 of 21
© Copyright Pearson Prentice Hall
2.2
Mixtures
>
Classifying Mixtures
Based on the distribution of their
components, mixtures can be classified
as heterogeneous mixtures or as
homogeneous mixtures.
Slide
5 of 21
© Copyright Pearson Prentice Hall
2.2
Mixtures
>
Classifying Mixtures
Heterogeneous Mixtures
A mixture in which the composition is not
uniform throughout is a heterogeneous
mixture.
Slide
6 of 21
© Copyright Pearson Prentice Hall
2.2
Mixtures
>
Classifying Mixtures
Homogeneous Mixtures
A mixture in which the composition is uniform
throughout is a homogeneous mixture.
Another name for a homogeneous mixture is a
solution.
Solution = solvent (lg. amt.) + solute (Sm.amt)
Slide
7 of 21
© Copyright Pearson Prentice Hall
2.2
Mixtures
>
Classifying Mixtures
The term phase is used to describe any
part of a sample with uniform composition
and properties.
• A homogenous mixture consists
of a single phase.
• A heterogeneous mixture consists of
two or more phases.
Slide
8 of 21
© Copyright Pearson Prentice Hall
2.2
Mixtures
>
Classifying Mixtures
When oil and vinegar are mixed they form layers,
or phases. The oil phase floats on the water
phase.
Slide
9 of 21
© Copyright Pearson Prentice Hall
Mixtures
>
Problem
Classify each of the following as a
homogeneous mixture or heterogeneous
mixture?
A brass ( an alloy of zinc and copper)
B. A salad
C. blood
D. powder milk mix dissolved in water
Ans.A. and D Homogeneous,
b and c heterogeneous
© Copyright Pearson Prentice Hall
Slide
10 of 21
Slide
11 of 21
© Copyright Pearson Prentice Hall
Slide
12 of 21
© Copyright Pearson Prentice Hall
Slide
13 of 21
© Copyright Pearson Prentice Hall
Practice Problems for Conceptual Problem 2.2
Problem Solving 2.10 Solve
Problem 10 with the help of an
interactive guided tutorial.
Slide
14 of 21
© Copyright Pearson Prentice Hall
2.2
Mixtures
>
Separating Mixtures
Separating Mixtures
How can mixtures be separated?
Slide
15 of 21
© Copyright Pearson Prentice Hall
2.2
Mixtures
>
Separating Mixtures
Differences in physical properties can
be used to separate mixtures.
Slide
16 of 21
© Copyright Pearson Prentice Hall
2.2
Mixtures
>
Separating Mixtures
Filtration
The process that separates a solid from the liquid
in a heterogeneous mixture is called filtration.
A colander is used to separate pasta from the
water in which it was cooked. This process is a
type of filtration.
Slide
17 of 21
© Copyright Pearson Prentice Hall
2.2
Mixtures
>
Separating Mixtures
Distillation
During a distillation, a liquid is boiled to
produce a vapor that is then condensed into a
liquid.
Slide
18 of 21
© Copyright Pearson Prentice Hall
Mixtures
>
Question!
Describe a method that could be used to
separate the following mixtures.
a. Iron filings and sand
b. Ans. A magnet can be use to draw the
filings out of the sand.
Slide
19 of 21
© Copyright Pearson Prentice Hall
Mixtures
>
Question continued
b. sand and salt
Ans: add water to the mixture to dissolve
the salt. Filter the mixture to remove the
sand and then boil off the water so only
the salt remains
Slide
20 of 21
© Copyright Pearson Prentice Hall
Mixtures
>
Question continued
c.The components of ink
Ans: paper chromatography should be
used to separate the components of
the ink.
Or Distillation if enough ink is available
Slide
21 of 21
© Copyright Pearson Prentice Hall
Mixtures
>
Question Continued
d. Helium and oxygen gases
Ans: cool the gas mixtures until it
condenses , then distill the condensate.
Slide
22 of 21
© Copyright Pearson Prentice Hall
Mixtures
>
Question
A mixture is the chemical bonding of two
or more substances in any proportion.
Is this statement true or false. Explain
Ans: False Mixtures are a physical blend
of substances, not a chemical bonding
of substances
Slide
23 of 21
© Copyright Pearson Prentice Hall
Mixtures
>
Problem
Slide
24 of 21
© Copyright Pearson Prentice Hall
2.2 Section Quiz.
1. Which of the following phrases describes a
mixture?
a. composition varies
b. composition may vary
c. components cannot be separated
Slide
25 of 21
© Copyright Pearson Prentice Hall
2.2 Section Quiz.
2. Which of the following is a homogeneous
mixture?
a. vinegar
b. iron filings in sand
c. chicken noodle soup
d. muddy water
Slide
26 of 21
© Copyright Pearson Prentice Hall
2.2 Section Quiz.
3. Which technique is used to separate
homogeneous mixtures?
a. filtration
b. distillation
c. magnetism
d. dissolving
Slide
27 of 21
© Copyright Pearson Prentice Hall
END OF SHOW
Homework
• Page 58 Write out question.
• 39, 42, 46, 43, 38