1.1-1.3 quiz

Question 1

how to find percent composition

Answer 1

1) multiply # of atoms by atomic mass to find mass/ element
2) sum results to find total formula mass
3) divide mass of each element by total mass and multiply by 100% to find percent of each element

Question 2

what does same empirical formula mean

same…

Answer 2

same percent composition by mass

Question 3

lowest whole number ratio of atoms

Answer 3

empirical formula

Question 4

actual # or atoms formula

Answer 4

chemical or molecular formula

Question 5

how to find # of neutrons

Answer 5

mass - atomic number(protons) = neutrons

Question 6

what is mass spectroscopy used for?

Answer 6

to calculate atomic mass
identifiy isotopes in element
find abundance in nature

Question 7

how to find empirical formulation

Answer 7

get rid of percent sign
match up to element and divide by actually grams of element on periodic table
then divide by lowest number of the two
then multiply those two numbers by the formula to get your answer

Question 8

how to find chemical/ molecular formula

Answer 8

divide molar mass by empirical formula mass to find factor

then multiply all subscripts in the empirical formula by the answer

Question 9

what number is used for formula units

Answer 9

avogadro’s number

6.02 * 10^23

Question 10

how to find average atomic mass

Answer 10

multiply relative abundance of isotope by mass of isotope

do that for each isotope then add them all up at the end to match it to an element in the periodic table by the # if grams

( for spectroscopy concert percentage yo demi al by moving decimal point)

Question 11

grams to atoms CO2 (what do you need to pay attention to)

Answer 11

oxygen has 2 so 2 mol O

Question 12

how to find empirical formula when given a formula

ex. c2SO4

Answer 12

you would simplify but this one can’t be simplified since O is already 1