Test 1 Measurements

Question 1

If you have a temperature in Fahrenheit, how would you convert it to Celsius?

Answer 1

F = (1.8 x C) + 32

C = (F – 32)/1.8

Question 2

Any quantity (except zero) raised to the zero power equals, What Number?

Answer 2

Any quantity (except zero) raised to the zero power equals one

Question 3

Whats an exact number?

Answer 3

Numbers not obtained using measuring devices are called exact numbers

Exact numbers and definitions are considered to have an infinite number of significant digits

Question 4

What are the rules for significant figures?

Answer 4

Nonzero digits are always significant

Captive zeros are always significant (e.g., 101)

Leading zeros are never significant (e.g., 0.35).

Trailing zeros are only significant when the number contains a decimal point (e.g., 0.10 or 1.0)

Question 5

What is the rule for adding or subtracting significant figures?

Answer 5

When adding or subtracting, keep the smaller number of decimal places

Question 6

What is the rule for multiplying or dividing significant figures?

Answer 6

When multiplying or dividing, keep the smaller number of significant figures

Question 7

What is Accuracy?

Answer 7

Accuracy—the agreement between experimental data and the “true” value

% error

Question 8

What is precision?

Answer 8

Precision—the agreement between replicate measurements

Standard deviation

Question 9

What is the formula for Kelvin?

Answer 9

K = (degrees)C + 273.15

Question 10

What is the formula for Density?

Answer 10

D = Mass / Volume

Question 11

What is matter?

Answer 11

Anything that has mass and occupies space

Question 12

What is a proton?

Answer 12

Protons—positively charged with a mass of approximately 1 atomic mass unit (amu)

Question 13

What is a Neutron?

Answer 13

Neutrons—electrically neutral and have a mass of approximately 1 amu

Question 14

What is an electron?

Answer 14

Electrons—negatively charged and have a much smaller mass than protons and neutrons

Question 15

What is a pure substance?

Answer 15

Pure substances (elements and compounds) are materials that cannot be physically separated into simpler components

Question 16

What is a mixture?

Answer 16

Mixtures are comprised of two or more pure substances and can be resolved into simpler components through physical processes

Question 17

What are the two types of mixtures you can have?

Answer 17

Homogeneous and Heterogeneous

Question 18

What is a Homogeneous mixture?

Answer 18

Homogeneous mixtures are uniform in chemical and physical properties (e.g. air, vodka)

Question 19

What is a Heterogeneous mixture?

Answer 19

Heterogeneous mixtures exhibit distinct phase boundaries between their components (e.g. blood, cereal in milk)

Question 20

What is an atomic number?

Answer 20

Atomic number (Z)—number of protons in the nucleus

Question 21

What determines the identity of an atom?

Answer 21

The atomic number

Question 22

What is a neutron number?

Answer 22

Neutron number (N)—number of neutrons in the nucleus

Question 23

What is an mass number of an atom?

Answer 23

Mass number (A)—sum of the atomic number and neutron number

Question 24

Elements are always electrically neutral, so each atom must have an equal number of what two particles?

Answer 24

Elements are always electrically neutral, so each atom must have an equal number of protons and electrons

Question 25

Name this compound:

N2O

Answer 25

Dinitrogen monoxide (commonly: nitrous oxide)

Question 26

Name this compound:

SCl2

Answer 26

Sulfur dichloride

Question 27

Whats an electrolyte?

Answer 27

An electrolyte is a substance that dissolves in water to give a solution that conducts electricity

Question 28

Whats a nonelectrolyte?

Answer 28

A nonelectrolyte is a substance that dissolves in water to give a solution that does not conduct electricity

Question 29

Which compounds are nonelectrolytes?

Answer 29

Molecular compounds are nonelectrolytes, unless they have acid or base properties

Question 30

What is avogadros number?

Answer 30

1 MOLE = 6.02 × 1023 particles/mol (Avogadro’s number)

Question 31

What is a mole?

Answer 31

A mole is an amount of a substance that contains exactly as many particles as there are in exactly 12 g of carbon-12