chapter 10

Question 1

how do you measure matter?

Answer 1

determine mass, or volume

Question 2

what is matter composed of?

Answer 2

atoms, molecules, ions.

Question 3

mole

Answer 3

6.02 *10^23 representative particles of that substance and is the SI unit for measuring the amount of a substance.

Question 4

avogadros number

Answer 4

the number of representative particles in a mole, 6.02*10^23

Question 5

representative particles

Answer 5

refers to the species presnt in a substance, usually atoms, molecules, or formula units.

Question 6

what is the representative particle of most elements?

Answer 6

atom

Question 7

what is the representative particle of all molecular compounds?

Answer 7

molecule

Question 8

What does the mole allow chemists to do?

Answer 8

count the number of representative particles in a substance.

Question 9

what is the conversion to convert between representative particles and moles?

Answer 9

1 mol over 6.02*10^23

Question 10

what must you know to determine how many atoms are in a mole of a compound?

Answer 10

you must know how many atoms are in a representative particle of a compound.

Question 11

What must you do to find the number of atoms in a given number of moles of a compound?

Answer 11

you must first determine the number of representative particles.

Question 12

What must you do to convert the number of moles of a compound to the number of representative particles?

Answer 12

multiply the number of moles by 6.02*10^23 representative particles. multiply the number of representative particles by the number of atoms in each molecule or formula unit.

Question 13

what is the atomic mass expressed in?

Answer 13

atomic mass units.

Question 14

what is the atomic mass of an element expressed in grams

Answer 14

the mass of a mole of the element

Question 15

molar mass

Answer 15

the mass of a mole of an element

Question 16

What must the molar mass of any two elements contain?

Answer 16

the same number of atoms.

Question 17

What does the molar mass of any element contain?

Answer 17

1 mol or 6.02*10^23 atoms

Question 18

What is molar mass

Answer 18

the mass of 1 mol of atoms of any element

Question 19

What is the molar mass of any compound

Answer 19

is the mass in grams of 1 mol of that compound

Question 20

how do you calculate the molar mass of a compound?

Answer 20

find the number of grams of each element in one mole of the compound. then add the masses of the elements in the compound.

Question 21

What is the molar mass of any substance the same as?

Answer 21

the mass in grams of one mole of that substance.

Question 22

Use the molar mass of an element or compound to convert between

Answer 22

the mass of a substance and the moles of the substance.

Question 23

avogadros hypothesis

Answer 23

states that equal volumes of gases at the same temperature and pressure contain equal numbers of particles.

Question 24

What do volumes of gas vary with?

Answer 24

a change in temperature or a change in pressure.

Question 25

standerd temperature and pressure.

Answer 25

means a temperature of 0 C and a pressure of 101.3 kPa, or 1 atmosphere.

Question 26

molar volume

Answer 26

volume of 22.4 L

Question 27

the molar volume is used to convert between what?

Answer 27

the number of moles of gas and the volume of the gas at STP

Question 28

what is the density of gas measured in?

Answer 28

grams per liter

Question 29

the density of a gas at STP and the molar volume at STP can be used to calculate

Answer 29

the molar mass of the gas.

Question 30

percent compostion

Answer 30

the relative amounts of the elements or the percent by mass of each element in the compound.

Question 31

What can you calculate if you know the relative masses of each element in a compound?

Answer 31

you cna calculate the percent composition of the compound.

Question 32

The percent by mass of an element in a compound

Answer 32

the number of grams of the element divided by the mass in grams of the compound, multiplied by 100%

Question 33

what can you use percent composition to calculate?

Answer 33

the number of grams of any element in a specific mass of a compound.

Question 34

empirical formula

Answer 34

gives the lowest whole number ratio of the atoms or moles of the elements in a compound.

Question 35

what does the molecular formula tell?

Answer 35

the actual number of each kind of atom present in a molecule of a compound.

Question 36

What can percent composition be used to calculate?

Answer 36

the empiracal formula of that compound

Question 37

What does the percent compostion tell?

Answer 37

the ratio of masses of the elements in a compound.