80 likes | 99 Views
FORMULA MASS. Also known as formula weight, molecular mass, molecular weight, molar mass or atomic mass. FORMULA MASS. 1) Write out the symbols (VERTICALLY) 2) Write out how many you have 3) Multiply by the atomic mass (3 SD) 4) Total up the masses (3 SD) EXAMPLE = Ag (NO 3 )
E N D
FORMULA MASS Also known as formula weight, molecular mass, molecular weight, molar mass or atomic mass
FORMULA MASS 1) Write out the symbols (VERTICALLY) 2) Write out how many you have 3) Multiply by the atomic mass (3 SD) 4) Total up the masses (3 SD) EXAMPLE = Ag (NO3) Ag 1 X 108 = 108. N 1 X 14.0 = 14.0 O 3 X 16.0 = 48.0 170.grams
Ca (NO3)2 Ca 1 X 40.1 = 40.1 N 2 X 14.0 = 28.0 O 6 X 16.0 = 96.0 164 grams
FORMULA MASS atomic mass chart EXAMPLE = K (Mn O4) K 1 X 39.1 = 39.1 Mn 1 X 54.9 = 54.9 O 4 X 16.0 = 64.0 158
CLASS WORKSHOW YOUR WORK!! 1) Na Cl 2) Li2 O 3) Al Br3 4) Sn2 S4 1) Mg (SO4) 2) K (ClO3) 3) Ca (OH)2 4) Be3 (PO4)2
FORMULA MASS CLASSWORK Choose a problem off of the front desk to do. (Due in before you leave) Home work is Formula Mass Problems from packet (1 to 15) Be sure to show your work. Watch out for problems #7, #9, and #10
FORMULA MASS HOMEWORK Cu(SO4) 5H2O The dot means ADD 5 water molecules Cu 1 X 63.5 = 63.5 S 1 X 32.1 = 32.1 O 4 X 16.0 = 64.0 TOTAL =249.7 H 10 X 1.01 = 10.1 250. O 5 x 16.0 = 80.0
HINTS GET A CALCULATOR ! • MULTIPLY WHEN USING THE DISTRIBUTIVE PROPERTY • ROUND OFF ATOMIC MASSES TO 3 SIGNIFICANT DIGITS • KEEP DECIMAL POINTS ALIGNED WHEN ADDING UP