Chapter 3: Chemical Rxns and Rxn Stoichiometry

Question 1

formula weight (FW)

Answer 1

• sum of atomic weights of each atom in a chemical formula
• unit = amu
• round answers to decimal places

Question 2

percent composition

Answer 2

-mass contributed by each element in a substance

Question 3

percent composition formula

Answer 3

% composition= (atomic weight/gfm) x 100

Question 4

chemical reactions

Answer 4

when chemicals are transformed into new chemicals

Question 5

chemical equations

Answer 5

symbolic representation of a chemical rxn

Question 6

law of conservation of matter

Answer 6

matter is neither created nor destroyed, only transformed

Question 7

avogadro’s number

Answer 7

6.022 x 10^23

Question 8

when do you write atoms or molecules as a unit?

Answer 8

• atoms= one element used

- molecules=more than one element used