Honors Chemistry Matter Unit Test Mrs Herrick WCHS

What is a physical property of matter?

A characteristic that can be observed or measured without changing the substance’s identity (e.g., color, density, melting point)

What is a chemical property of matter?

A characteristic that describes how a substance can change into a new substance (e.g., flammability, reactivity with oxygen)

What is an intensive property?

A physical property that does not depend on the amount of matter present (e.g., density, color, boiling point)

What is an extensive property?

A physical property that depends on the amount of matter present (e.g., mass, volume, total energy)

What is the main difference between intensive and extensive?

Intensive= independent of amount

Extensive= depends on amount

What is a physical change?

A change that alters a substance’s appearance or state but does not create a new substance (e.g., melting ice, cutting paper)

What is a chemical change?

A change where atoms rearrange to form one or more new substances (e.g., rusting iron, burning wood, baking a cake)

What are some signs a chemical change has occurred?

• Gas produced (bubbles)

• Color change

• Temperature change

• Formation of a solid (precipitate)

Is density an intensive or extensive property?

Intensive— it does not depend on how much substance you have

Is mas an intensive or extensive property?

Extensive— it depends on the amount of matter

What are the two main categories of matter?

Substances and mixtures

What is a substance?

Matter with a fixed composition (e.g., elements, compounds)

What is a mixture?

Matter made of two or more substances physically combined, can be homogeneous or heterogeneous

What is an element?

A substance made of only one type of atom, represented by a chemical symbol (e.g., Oxygen, Iron)

What is a compound?

A substance made of two or more elements chemically combined, represented by a chemical formula (e.g., water, carbon dioxide)

What is a homogeneous mixture?

A mixture that is uniform throughout, also called a solution (e.g., salt water, air)

What is a heterogeneous mixture?

A mixture that is not uniform; you can see different parts (e.g., salad, sand and water)

How can you classify matter using a periodic table?

Elements are listed on the periodic table by their chemical symbol. Compounds are combinations of these elements

How can particle drawings help classify matter?

• Elements: all identical particles

• Compounds: all particles identical, but made of multiple atoms

• Homogeneous mixtures: particles evenly mixed

• Heterogeneous mixtures: particles clumped or layered

What is the key idea about separating mixtures?

Mixtures can be separated using physical changes only, because no new substances are formed

What is filtration used for?

Separates solids from liquids using a filter (e.g., sand from water)

What is evaporation used for?

Separates a soluble solid from a liquid by boiling off the liquid (e.g., salt from salt water)

What is distillation used for?

Separates liquids with different boiling points (e.g., alcohol from water)

What is magnetic separation used for?

Separates substances based on magnetism (e.g., iron filings from sand)

What is chromatography used for?

Separates soluble substances based on how far they travel on a surface (e.g., pigments in ink or leaves)

What is centrifugation used for?

Separates mixtures by density using rapid spinning (e.g., separating blood components)

What property do all separation techniques rely on?

Physical properties like particle size, solubility, boiling point, density, or magnetism

When solving problems about separating mixtures, what should you do first?

Identify the physical properties of the components that allow separation. Then choose the appropriate technique 

What does the Law of Conservation of Mass state?

Mass cannot be created or destroyed in a chemical or physical change; the total mass before= the total mass after

Give a real-world example of the law of conservation of mass with a physical change

Melting ice: the mass of ice= mass of water after melting

Give a real-world example of the law of conservation of mass with a chemical change

Burning wood in a closed container: mass of wood + oxygen= mass of ash + gases

How do you solve problems using the law of conservation of mass?

1. Write down total mass before the change

2. Write down mass of known products

3. Use mass before= mass after to find unknown mass

What is the Law of Definite Proportions?

A chemical compound always contains the same elements in the same proportion by mass, no matter the sample size (e.g., water is always 2 H : 1 O by atoms or 11.2% H and 88.8% O by mass)

What is the Law of Multiple Proportions?

When two elements form more than one compound, the masses of one element that combine with a fixed mass of the other are in small whole-number ratios (e.g., CO and CO2 → 12g C combines with 16 g O (CO) or 32 g O (CO2), ratio = 1:2)

How do you solve percent composition problems?

1. Find molar mass of compound

2. Divide mass of element/ total molar mass x 100

How do you solve law of multiple proportions problems?

1. Determine the mass ratio of one element that combines with a fixed mass of the other

2. Simplify the ratio to small whole numbers

What are the three main phases of matter and their general properties?

Phase	Particle Arrangement	Particle Movement	Shape/Volume
Solid	Tightly packed	Vibrate in place	Definite shape & volume
Liquid	Close but not fixed	Slide past each other	Definite volume, takes shape of container
Gas	Far apart	Move freely	No definite shape or volume

How can you determine a substance’s phase using temperature?

• Compare temperature to melting/freezing point and boiling/condensation point

• Below melting point: solid

• Between melting & boiling: liquid

• Above boiling point: gas

What is a heating curve?

A graph showing temperature vs. heat added

• Flat sections: phase changes

• Sloped sections: temperature change of a single phase

How do particle drawings look in each phase?

• Solid: particles close together, mostly vibrating

• Liquid: particles close but sliding past each other

• Gas: particles far apart, moving freely

How do you interpret a heating/cooling curve?

• Flat lines →phase change, temperature constant

• Sloped lines →temperature changing, single phase

• Use boiling/melting points to label phases on the curve