2.1 Mixtures

UNIT 2; SEPARATION TECHNIQUES

2.1 MIXTURES

Lesson objectives;

At the end of this lesson, you should be able to;

• Tell the differences between mixtures and compounds

• Explain how to identify pure substances

Multiple Choice

TRUE or FALSE

You brushed your teeth today

• TRUE

• FALSE

Multiple Choice

Page 72;

TRUE or FALSE

Toothpaste is a mixture

• TRUE

• FALSE

Multiple Choice

Page 72;

TRUE or FALSE

A mixture is made up of several different substances

• TRUE

• FALSE

Multiple Choice

TRUE or FALSE;

A mixture is a physical combination of two or more substances that are chemically joined together

• TRUE

• FALSE

Multiple Choice

TRUE or FALSE;

A mixture is a physical combination of two or more substances that are not chemically joined together

• TRUE

• FALSE

Multiple Choice

Page 72; What can you use to separate a mixture of Sulphur and Iron?

• Magnet

• Electricity

• Stick

• Water

Multiple Select

Page 72; A magnet can be used to separate a mixture of Sulphur and iron because; (select 3 answers)

• Iron sticks to the magnet but Sulphur doesn't

• Iron is a metal so it sticks to the magnet and the Sulphur remains behind

• Sulphur sticks to the magnet but Iron doesn't

• Sulphur is not ferromagnetic

Multiple Choice

Page 72; True or false;

In compounds, atoms of different elements are strongly joined together

• TRUE

• FALSE

Multiple Choice

Page 72; How could you separate atoms of elements in a compound?

• Using a chemical reaction

• Using a magnet

Multiple Select

Google this;

What is a compound?

• A compound is a material formed by chemically bonding two or more chemical elements

• a substance made from two or more different elements that have been chemically joined.

• A compound is a pure substance that can be broken down into elements

• any substance composed of identical molecules consisting of atoms of two or more chemical elements

• a substance formed when two or more chemical elements are chemically bonded together.

Multiple Choice

Use the table on page 72 to answer the next 12 questions.

Mixtures or compounds?

They are pure substances.

• Mixtures

• Compounds

Multiple Choice

Mixtures or compounds?

They are impure substances.

• Mixtures

• Compounds

Multiple Choice

Mixtures or compounds?

They are made up of two or more elements combined chemically

• Mixtures

• Compounds

Multiple Choice

Mixtures or compounds?

They are made up of two or more elements combined physically

• Mixtures

• Compounds

Multiple Choice

Mixtures or compounds?

The constituents are present in varying ratios.

• Mixtures

• Compounds

Multiple Choice

Mixtures or compounds?

The constituents are present in a fixed ratio.

• Mixtures

• Compounds

Multiple Choice

Mixtures or compounds?

Have fixed properties. For example, a particular fixed temperatures at which it melts and boils.

• Mixtures

• Compounds

Multiple Choice

Mixtures or compounds?

Do not have fixed properties. Their properties depend on the nature of their compo­nents and the ratios in which they are combined.

• Mixtures

• Compounds

Multiple Choice

Mixtures or compounds?

..... can have properties different from its constituents, as a new substance is formed when the constituents are chemically combined.

• Mixtures

• Compounds

Multiple Choice

Mixtures or compounds?

.........no new substance is formed. The properties are the same as the properties of its constituents.

• Mixtures

• Compounds

Multiple Choice

Mixtures or compounds?

The constituents can be separated easily by physical methods.

• Mixtures

• Compounds

Multiple Choice

Mixtures or compounds?

The constituents can be separated only by chemical methods.

• Mixtures

• Compounds

Multiple Choice

Page 72;

One way to identify pure substances is a lab is to heat them until they reach their melting point.

A(n) ______ substance has a _____ melting point

• pure, sharp

• impure, sharp

• pure, continuous

• impure, continuous

Multiple Choice

The graph shows the temperature rise of two substances over a period of time. Which of the two is impure?

• Green substance

• Red substance

Multiple Choice

The graph shows the temperature rise of two substances over a period of time.

Which of the two is pure? Why?

• Green substance, melting section is continuous

• Red substance, melting section is conntinous

• Green substance, melting section is sharp

• Red substance, melting section is sharp

Multiple Choice

Which of these graphs represents a compound?

• The graph on the right

• The graph on the left

Multiple Choice

Page 73; True or false?

Most rocks are mixtures of compounds.

• TRUE

• FALSE

Multiple Choice

Page 73; What's the use of each of these toothpaste components?

hydrated silica

• removes plaque

• prevents cavities

• makes foam

• thicken the toothpaste

• whiten the teeth

Multiple Choice

Page 73; What's the use of each of these toothpaste components?

sodium fluoride

• removes plaque

• prevents cavities

• makes foam

• thicken the toothpaste

• whiten the teeth

Multiple Choice

Page 73; What's the use of each of these toothpaste components?

sodium lauryl sulphate

• removes plaque

• prevents cavities

• makes foam

• thicken the toothpaste

• whiten the teeth

Multiple Choice

Page 73; What's the use of each of these toothpaste components?

carrageenan

• removes plaque

• prevents cavities

• makes foam

• thicken the toothpaste

• whiten the teeth

Multiple Choice

Page 73; What's the use of each of these toothpaste components?

titanium oxide

• removes plaque

• prevents cavities

• makes foam

• thicken the toothpaste

• whiten the teeth

Toothpaste box design challenge

• Use an online drawing software of your choice to design a toothpaste box.

• Make up ingredients and include them on the box

• Write down a reason why each ingredient is included.

• Submit your work on google classroom (use the template provided).

• EXTRA CREDIT IF YOU DESIGN IT IN REAL LIFE!