7.3

Formula Mass – for any molecule, formula unit, or ion, it is the ____ of the ________ masses of all atoms represented in its formula. H 2 O for example is H = x 2 = amu O = x 1 = amu Total = amu

Try to find the mass of KClO 3 H 2 SO 4 Ca(NO 3 ) 2 PO 4 3- MgCl 2

The mass of 1 mol of a substance in g/mol H 2 O for example is H = x 2 = g/mol O = x 1 = g/mol Total = g/mol The ___ 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 H 2 O? How many moles are in 10 grams of Carbon? molecules of CH 4 ? How many moles are in 3.01 x molecules of CH 4 ? How many atoms are in 15 moles of S? How many atoms are in 15 moles of S?

How many molecules are there in the following… 25.0 g H 2 SO g Sugar C 6 H 12 O 6 How many grams are in… 6.5 x atoms of Cu 5.12 x molecules of CH 4

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 Al 2 O 3. Determine the composition of Al, S, and O in Al 2 (SO 4 ) 3

Find the % comp of each element in the following PbCl 2 Ba(NO 3 ) 2 Find the % water in ZnSO47H 2 O Mg(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!