Chemistry March 10 & 11, 2016

•OBJECTIVE: Students will solve mole-mass problems orally and in writing.

•W.O.D. Vivacious-lively, spirited, full of life

•WARM-UP

1.Complete the statement: 1 mole of any substance = ______________ in grams

2.How is the molar mass of an element determined?

3.What is the molar mass of carbon?

HW

•Page 315 #9-15

CW

Mole-mass problems

•1 mole of an element = atomic mass expressed in grams.

•1 mole of a compound = molar mass expressed in grams

•To calculate the molar mass of a compound, multiply the atomic mass of each element by the number atoms of that element in the formula, then add the masses.

Find the Molar mass of each of the following:

• PCl3

•NaHCO3

•C20H42

•Fe(OH)2

•N2O3

•Mg3(PO4)2

•Ba(NO3)2

•Carbon tetrafluoride

•Lithium

•Molecule of nitrogen

•How many moles are in

a.45g PCl3

b.250g NaHCO3

c.84g C20H42

d.2 x 103 g Fe(OH)2

e.4.5 x 102 g N2O3

•What is the mass of

a.2 moles Mg3(PO4)2

b.3.5 moles Ba(NO3)2

c.0.14 moles carbon tetrafluoride

d.2.4 x 10-3 moles lithium

e.25 moles NaCl