Solving Stiochemistry
Rebecca Ledezma (Period 5)
NAME OF REACTION
& Strontium Nitrate Sr(NO3)2
TYPE OF REACTION
BALANCED EQUATION
To be a balanced equation, it must have the same amount of each element on the reactant side as the product side. When writing an equation for double replacement, you must also have the states of matter for each compound.
IUPAC NAMING
MOLAR MASS
To find the Molar mass for each element, look at the periodic table. You multiply the mass by any subscript or coefficient meant for the element.
Na: 22.99 (2) + S: 32.066 (1) + O: 15.99(4) = 142.042 g
Sr(NO3)2
Sr: 87.62 (1) + N: 14.007 (2) + O: 15.99 (6) = 211.628 g
NaNO3
Na: 22.99 (1) + N: 14.007 (1) + O: 15.99(3) = 84.967 g
SrSO4
Sr: 87.62 (1) + S: 32.006 (1) + O: 15.99(4) = 183.662 g
MOLE TO MOLE CONVERSIONS
8.25 mole Na2SO4 • 1 mole Sr(NO3)2
________________________________________ = 8.25 mole Sr(NO3)2
1 mole Na2SO4
8.25 mole NaNO3 • 1 SrSO4
______________________________ = 4.125 mole SrSO4
2 mole NaNO3
MASS TO MASS CONVERSION
______________________________________
142.042 g Na2SO4
= 18.03 g Sr(NO3)2
*look at chart for guidance*
LIMITING & EXCESS REACTANT
Excess: element left over
In the Smore's lab, the limiting reactant was the chocolate. The excess reactant was the crackers and marshmallows.
12.3 g Na2SO4 • 1 • 2 • 107.78 NaNO3
_______________________________________ = 18.66 g NaNO3
142.042 Na2SO4 •1 • 1 NaNO3
*12.3 g of Na2SO4 is your excess reactant*
THEORETICAL YIELD
12.3 g Sr(NO3)2 • 1 • 2• 107.78 NaNO3
________________________________________ = 12. 53 g NaNO3
211.628 Sr(NO3)2 •1 • 1 NaNO3
* 12.3 g of Sr(NO3)2 is your limiting reactant*
*12.53 g NaNO3 is your theoretical*
PERCENT YIELD
Actual Yield: 13. 42 g NaNO3
13.42/12.53 • 100 = 107.1%
BACKGROUND OF REACTION
STRONTIUM NITRATE: Used in the production of color tv tubes, sources are Mexico, Iran, Turkey, and Spain