7.3

Formula Mass – for any molecule, formula unit, or ion, it is the ____ of the ________ masses of all atoms represented in its formula.

H2O for example isH = 1.008 x 2 = 2.016 amuO = 15.999 x 1 = 15.999 amuTotal = 18.015 amu

Try to find the mass of KClO3 H2SO4

Ca(NO3)2 PO43-

MgCl2

The mass of 1 mol of a substance in g/mol

H2O for example isH = 1.008 x 2 = 2.016 g/molO = 15.999 x 1 = 15.999 g/molTotal = 18.015 g/molThe ___ mass is numerically = to the ___ mass

You can convert grams to moles and vice versa using ______ ______

You can also convert atoms to moles and vice versa using ___________ #

What is the mass in grams of 2.50 mol of oxygen gas?

How many moles are in 100 g of H2O?How many moles are in 10 grams of Carbon?

How many moles are in 3.01 x 1023 molecules of CHmolecules of CH44??

How many atoms are in 15 moles of How many atoms are in 15 moles of S?S?

How many molecules are there in the following…

25.0 g H2SO4

125 g Sugar C6H12O6

How many grams are in…6.5 x 1023atoms of Cu5.12 x 1030 molecules of CH4

Percent Composition – the % by mass of each _________ in a cmpd

To calculate % Comp, determine _______ mass of entire compound.

Calculate the % of each element by __________ the mass of each ___________ by the molar mass.

Determine the percent composition of Al and O in Al2O3.

Determine the composition of Al, S, and O in Al2(SO4)3

Find the % comp of each element in the following

PbCl2 Ba(NO3)2

Find the % water in ZnSO4•7H2OMg(OH)2 is 54.87% O by mass. How many g of O are in 175 g of the cmpd? How many moles of O is this?

Complete the section review on page 244 numbers 1-6. This is due at the beginning of class tomorrow!