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The Sum of Coefficients
You may be asked to provide the sum of the coefficients.
This means that you must add up all the coefficients (numbers in front of the molecules) in the entire equation.
If there is no number in front of the molecule, add a one.
What is the sum of coefficients of the following equation? Ca(OH)2 + (NH4)2 SO4 CaSO4+ 2NH3 + 2H2O
1. Add a one to any molecule that doesn’t have a coefficient: 1 Ca(OH)2 + 1 (NH4)2 SO4 1 CaSO4+ 2NH3 + 2H2O
2. Add all the coefficients.
1 Ca(OH)2 + 1 (NH4)2 SO4 1 CaSO4+ 2NH3 + 2H2O
1+1+1+2+2=7
The sum of the coefficients is 7.
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