chem 151 test 1

Explain the scientific method

1. Make observations.

2. Explain why (hypothesis).

3. Test hypothesis, revise hypothesis.

Law

Statement of fact

Theory

Explanation

What is chemistry

Study of matter

What is matter

Anything that has mass and volume

What is the volume and shape of a solid

Definite, definite

What is the volume and shape of a liquid

Definite, takes on shape of container

What is the volume and shape of gas

No definite volume, no definite shape

Describe the particles of a solid

Particles are tightly packed

Describe the particles of a liquid

Particles are closely packed

Describe the particles of a gas

Particles are far apart

How do you convert a solid to a liquid, a liquid to gas and a solid to a gas

Increase the temperature(decreasing the temperature do the opposite)

How do you convert a gas to a liquid, liquid to gas, and gas to solid

Increase the pressure ( decreasing dos the opposite)

Pure substance components

Single component, uniform composition

Mixture components

Two or more components, composition varies between samples

Can pure substances be broken down into simpler substances by physical changes?

No

What is a compound

Pure substance formed by chemically combining two or more elements

Can a mixture be broken down into simpler substances by physical changes ?

Yes

Chemical properties

Describe the way a substance may react to form other substances.

Ex. flammability, reactivity

Physical properties

Observed or measured without changing the composition of the material.

Ex. melting point, boiling point, solubility, color, density

Chemical changes

convert one material to another (chemical reaction).

Ex. fire

4 Indicators of chemical change

1. Color change

2. Temperature change

3. Formation of a solid

4. Formation of a gas

Physical changes

do not change the composition of the material.

Ex. melting, boiling, freezing

What are the three states of matter?

Solid, liquid, gas

Metric system base units

Length, meter (m)

Volume, liter (L)

Mass, gram (g)

Base unit of length

Meter

Base unit of volume

Liter

Base unit of mass

Kilogram

What is mass?

Mass is the amount of matter in an object.

Describe weight

Weight is the force that matter feels due to gravity.

What are the three different temperature scales

Celsius, Fahrenheit, Kelvin

What is a measurement?

Number and a unit

How do you solve for density?

Mass/volume

1in

2.54cm

1kg

2.20lbs

1gal

3.785L

Formula for kelvin

K= °C +273

Formula for Fahrenheit

°F= (1.8 x °C)+32

Formula for Celsius

°C= (°F-32)/1.8

Who first proposed that reality is made of atoms and empty space?

Democritus

What was Democritus’ main idea about matter?

All matter is composed of atoms.

Who is regarded as the father of modern chemistry?

Lavoisier

What major law did Lavoisier discover?

Law of Conservation of Mass.

What does the Law of Conservation of Mass state?

In a chemical reaction, the mass of reactants equals the mass of products