Textbook Ch.1: Matter and Measurements

Question 1

Pure substance

Answer 1

• Elements or compounds

- Have fixed compositions and a unique set of properties

Question 2

Mixture

Answer 2

• Homogeneous or heterogeneous

- Composed of two or more substances that are combined in such a way that each substance retains its chemical identity

Question 3

Element

Answer 3

a type of matter that cannot be broken down into two or more pure substances

Question 4

Compound

Answer 4

• a pure substance that contains more than one element

- have fixed compositions

Question 5

Homogeneous

Answer 5

a uniform mixture in which the composition is the same throughout

Question 6

Solution

Answer 6

• another name for a homogenous mixture
• made up of a solvent, usually taken to be the substance present in the largest amount
• also made of one or more solutes
• most commonly a solvent is a liquid and solutes can be solids, liquids, or gases

Question 7

Heterogeneous

Answer 7

non uniform mixtures are those in which the composition varies throughout

Question 8

Filtration

Answer 8

• A separation technique used to separate a heterogeneous solid-liquid mixture
• The mixture is passed through a barrier with fine pores

Question 9

Distillation

Answer 9

• Used to resolve a homogeneous solid-liquid mixture
• The liquid evaporates leaving a residue of the solid in the distilling flask, the liquid is obtained by condensing the vapor

Question 10

Chromatography

Answer 10

a more versatile separation method that is widely used in teaching, research, and industrial laboratories to separate all kinds of mixtures by taking advantage of differences in solubility and/or extent of adsorption on a solid surface

Question 11

What is the standard unit of length in the metric system?

Answer 11

meter

Question 12

Volume

Answer 12

the amount of space that a substance or object occupies

Question 13

What units can volume be expressed in?

Answer 13

• Cubic centimeters (cm³)
• Liters (L)
• Milliliters (mL)
• • 1mL = 1 cm³ **

Question 14

Mass

Answer 14

the amount of matter in a substance

Question 15

Temperature

Answer 15

the factor that determines the direction of heat flow

Question 16

What is the formula that relates temperature conversion between Celsius and Fahrenheit?

Answer 16

Tբ = 1.8T꜀ + 32

Question 17

Significant figures

Answer 17

the method of citing the degree of uncertainty with measurement

Question 18

What is the rule for significant figures when quantities are multiplied or divided?

Answer 18

the significant figures in the result is the same as that in the quantity with the smallest number of significant figures

Question 19

What is the rule for significant figures when quantities are added or subtracted?

Answer 19

the number of decimal places in the result is the same as that in the quantity with the smallest number of decimal places

Question 20

What are the rules for “rounding off” measurement when…

The digits to be discarded are less than 500?

Answer 20

leave the last digit unchanged

• Masses of 23.315 g and 23.487 g both round off to 23 g if only two significant digits are required

Question 21

What are the rules for “rounding off” measurement when…

The digits to be discarded are greater than 500?

Answer 21

add one to the last digit

• Masses of 23.692 and 23.514 g round off to 24 g

Question 22

What are the rules for “rounding off” measurement when…

The digits to be discarded are 500?

Answer 22

round off so that the last digit is an even number

• Masses of 23.500 g and 24.5 g both round off to 24 g

Question 23

Conversion factor

Answer 23

what you follow when wanting to convert a measurement expressed in one unit (e.g. cubic centimeters) to another unit (e.g. liters).
E.g.: 1L = 1000cm³

Question 24

Extensive properties

Answer 24

• Ex: mass and volume

- Properties that depend on the amount

Question 25

Chemical properties

Answer 25

observed when the substance takes part in a chemical reaction, a change that converts it to a new substance

Question 26

Physical properties

Answer 26

observed without changing the chemical identity of a substance

Question 27

Melting point

Answer 27

- An example of a physical property | - The temperature at which a substance changes from the solid to the liquid state

Question 28

Boiling point

Answer 28

- An example of a physical property | - the temperature at which bubbles filled with vapor within a liquid

Question 29

Density

Answer 29

the ratio of mass to volume - An intensive (not extensive property), (e.g. all copper has the same density) ``` density = mass/volume d = m/v ```

Question 30

The process by which a solute dissolves in a solvent is what type of change?

Answer 30

Physical

Question 31

Saturated

Answer 31

being a solution that is unable to absorb or dissolve any more of a solute at a given temperature and pressure

Question 32

Unsaturated

Answer 32

capable of absorbing or dissolving more of something

Question 33

Supersaturated

Answer 33

containing an amount of a substance greater than that required for saturation as a result of having been called from a higher temperature to a temperature below that at which saturation occurs