(TG) Mass to Mass Conversions

MASS TO MASS CONVERSIONS: A Process

• Mass to mass problems involve one addition conversion
• This can best be described through the following diagram/process:     

 The Three Step Process:

START WITH GRAMS OF 'A'

(1 step)

CHANGE TO MOLES OF 'A'

(2 step)

CHANGE TO MOLES OF 'B'

(3 step)

END UP WITH GRAMS OF 'B'

EXAMPLES:


Lead (IV) Nitrate reacts with 5.0g of Potassium Iodide. How many grams of Lead (IV) Nitrate are required for a complete reaction? (this example includes the LONG way of the process)

Pb(NOthree)four + 4KI ----> PbIfour + 4KNOthree

5g of KI (multiplied by) 1 mol/166g = .0301 mol

.0301 (multiplied by) 1/4 = .007525

.007525 (multiplied by) 455.2g/mol =

3.4 GRAMS of LEAD (IV) NITRATE 

How many grams of Otwo are produced from the decomposition of 3.0g of Potassium Chlorate (This example includes the FAST way of the process)

2KClOthree ----> K + Cltwo + 3Otwo

3.0 grams (multiplied by) mol/122.6g (multiplied by) 3/2 (multiplied by) 32g/mol =

1.2g

ALWAYS REMEMBER TO COUNT YOUR SIG FIGS!!!