Unit 6 Exam

Question 1

How to find missing coefficient of water molecules

Answer 1

find grams of water
grams of dry substance
convert both to mols
divide, smallest number on top
round quotient to a whole number

Question 2

How to find empirical formula

Answer 2

get grams of each element
convert all to mols
write mols number as subscript for each element
divide all by smallest subscript
if one isn’t a whole number, multiple all by a number to make it a whole number!

Question 3

How to find molecular formula

Answer 3

start with empirical formula
find molar mass
put the given molar mass over the empirical molar mass
round quotient to whole number
multiple whole number by empirical formula!