Unit 7: Stoichiometry

Question 1

Define gram formula mass (AKA Molar mass)

Answer 1

Mass of one mole of a substance

Question 2

During all chemical reactions what 3 things are on conserved

Answer 2

Mass, energy, and charge

Question 3

The law of conservation of mass states that….

Answer 3

matter cannot be created or destroyed

number of atoms equals number of atoms

Question 4

What is the molar mass of N2

Answer 4

28 g/mol= 2(14)
On the periodic table the mass of Nitrogen is 14.0067
14 is multiplied two times because it is N2

Question 5

What is the gram formula mass for Pb(C2H3O2)2

Answer 5

207. 2+4(12)+6(1.01)+4(16)

325. 26 g/mol

Question 6

define a mole as it pertains to chemistry

Answer 6

amount of substance quantity

Question 7

what is the total number of moles in 94.3g of NaCl?

Answer 7

x= 94.3/58.3

1.6 mol

Question 8

A sample of a compound contains 58.7 grams of Nickel, 32.1 grams of sulfur, and 48 grams of oxygen. What is the mole ratio of Nickel to Sulfur to Oxygen in this compound?

Answer 8

1:1:3
58.7/58.7=1 Nickel
32.1/32.1= 1 Sulfur
48/16=3 Oxygen