Quiz 3 Material (Avogadro's Number)

Question 1

what is a mole?

Answer 1

a collection that contains 6.022 x 10^23 of an element

Question 2

Avogadro’s Number

Answer 2

6.022 x 10^23 atoms

Question 3

__ mole of any atom is ___

Answer 3

one; avogadro’s number

Question 4

a mole of a covalent compound has

Answer 4

avogadro’s number of particles

Question 5

a mole of an ionic compound contains

Answer 5

avogadro’s number of formula units

Question 6

avogadro’s number is used to convert ___ to ___

Answer 6

moles of a substance, particles

Question 7

how many Cu atoms are in 0.50 mole of Cu?

Answer 7

3.0 x 10^23 Cu atoms

Question 8

how many moles of CO2 are in 2.50 x 10^24 molecules of CO2?

Answer 8

4.15 moles of CO2

Question 9

how many atoms are in 2.0 moles of Al?

Answer 9

1.2 x 10^24 atoms Al

Question 10

how many moles of S are in 1.8x 10^24 atoms of S?

Answer 10

3.0 moles

Question 11

the subscripts in a formula give…

Answer 11

the relationships of atoms in the formula, and the moles of each element in 1 mole of a compound

Question 12

how many moles of C, H, and O are in one moles of C9H8O4?

Answer 12

9 moles C
8 moles H
4 moles O

Question 13

how many O atoms are in 0.150 mole of aspirin (C9H8)4)? explain.

Answer 13

3.61 x 10^23; multiply moles aspirin by moles O, then multiply by Avogadro’s number

Question 14

formula weight

Answer 14

sum of the atomic weights of all the atoms in a compound

Question 15

how do we calculate formula weight?

Answer 15

multiply the number of atoms in each element by the atomic weight and add the results

Question 16

molar mass

Answer 16

the mass of one mole of any substance (atomic weight)

Question 17

define the molar mass of potassium

Answer 17

39.10 g/mol

Question 18

define the molar mass of Sn

Answer 18

118.71 g/mol

Question 19

define the molar mass of CaCl2

Answer 19

110.98 g/mol

Question 20

what is the molar mass of Prozac (C17H18F3NO)?

Answer 20

309.29 (answer may be slightly off due to decimal differences

Question 21

which compounds must be simplified when possible?

Answer 21

ionic compounds, NOT molecular

Question 22

how many grams of Al are in 3.00 moles of Al?

Answer 22

81.0 g of Al

Question 23

how many moles of aspartame (C14H18N2O5) are present in 225 g of aspartame?

Answer 23

0.765 mol

Question 24

to get to grams of an element/compound from moles of an element or compound, we must

Answer 24

use the molar mass

Question 25

to get to atoms/ions or molecules/formula units from moles, we must

Answer 25

use avogadro’s number