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Stoichiometry. STOICHIOMETRY the study of the quantitative relationships that exist in chemical formulas and reactions. The key to understanding… The coefficients in a balanced equation give the relative amounts (in moles) of reactants and products.
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STOICHIOMETRYthe study of the quantitative relationships that exist in chemical formulas and reactions
The key to understanding…The coefficients in a balanced equation give the relative amounts (in moles)of reactants and products.
The coefficients represent moles…2NaCl 2Na + Cl2 2 There are ____ moles of salt. There are ____ moles of sodium. 2 There is ____ mole of diatomic Cl. 1
Sample Problem If you start with 50g of salt, how many grams of chlorine are produced when the salt is decomposed?
STEP 1 Write the balanced equation!
STEP 2 Find the number of moles of the given substance
STEP 3 Use the balanced equation to find the ratio of moles of given substance to moles of needed substance
STEP 4 Convert moles of needed substance to whatever quantity is desired
No way!! Do you think that in the chemistry lab that we always get the amount of product that we calculate?
% Yield actual amount of a product expressed as a % of the theoretical amount of that substance
Percent Yield Actual amount of product from the lab % Yield = Calculated amount from stoichiometry