Class Opener: Friday, October 4

• A student has a 1 mole sample of silver and a 1 mole sample of gold.

a) Which sample contains the greatest number of atoms? How many atoms are in each sample?

b) Which sample has the greatest mass? What is the mass of each sample?

c) The current price of gold is $42.37 per gram. How much is the gold sample worth?

Mole Conversions• Many times in chemistry, you will need to express a

measurement in a unit different from the one given or measured initially.

• Conversion factor = ratio of equivalent measurements used to convert from one unit to another. (take form of a fraction)

Label Number Used in Conversion Factor

Mole 1

Atoms 6.02 x 1023

Mass (grams) Molar Mass (Atomic Mass)

Mole Conversion Problems

• A chemist produced 11.25 g of magnesium, Mg. How many moles of magnesium were produced?

• Determine the number of silver atoms that are contained in 0.650 mol Ag?

• Calculate the mass, in grams, of 3.07 x 1024 atoms of sulfur (S).

One Minute Paper• You have one minute to answer these two

questions concerning today’s lesson.

– What was the most important thing you learned?

– What is still muddy?