Gravimetric Stoichiometry

Stoichiometry a measure of the relative proportions of the elements that take part in a chemical reaction 4 Al (s) + 3 O2 (g) = 2 Al2O3 (s) 6.49 g ? mol g/mol

Stoichiometry a measure of the relative proportions of the elements that take part in a chemical reaction 4 Al (s) + 3 O2 (g) = 2 Al2O3 (s) 6.49 g ? mol g/mol n Al = m/M = 6.49g/26.98g/mol = mol n O 2 = n Al x mole ratio

Stoichiometry a measure of the relative proportions of the elements that take part in a chemical reaction 4 Al (s) + 3 O2 (g) = 2 Al2O3 (s) 6.49 g ? mol g/mol nAl = m/M = 6.49g/26.98g/mol = mol nO2 = nAl x mole ratio mol Al x 3 mol O 2 4 mol Al mol O mol O 2 *example from

Gravimetric Stoichiometry Gravimetric stoichiometry is stoichiometry with the answer expressed in mass. n Al 2 O 3 = n O 2 x mole ratio = mole O 2 x 2 mol Al 2 O 3 3 mol O 2 = mol Al 2 O 3

Gravimetric Stoichiometry Gravimetric stoichiometry is stoichiometry with the answer expressed in mass. nAl2O3 = nO2 x mole ratio = mole O2 x 2 mol Al2O3 3 mol O2 = mol Al2O3 m Al 2 O 3 = n x M = mol x g/mol = g =12.26g of Al 2 O 3 *example from

Gravimetric Stoichiometry 1) Which word is most closely associated with meaning of the term gravimetric? A ) density B ) mass C ) mole D ) volume 2) Which device is best suited to obtaining a specific mass of a chemical species? A ) balance B ) beaker C ) flask D ) graduated cylinder

Gravimetric Stoichiometry 1) Which word is most closely associated with meaning of the term gravimetric? A ) density B ) mass C ) mole D ) volume 2) Which device is best suited to obtaining a specific mass of a chemical species? A ) balance B ) beaker C ) flask D ) graduated cylinder

Gravimetric Stoichiometry 1) Which word is most closely associated with meaning of the term gravimetric? A ) density B ) mass C ) mole D ) volume 2) Which device is best suited to obtaining a specific mass of a chemical species? A ) balance B ) beaker C ) flask D ) graduated cylinder

Gravimetric Stoichiometry 3) What mass of aluminum oxide can be produced from the complete reaction of mol of oxygen gas? 4Al (s) + 3O (g) = 2Al 3 O 2 A ) 13.8 g B ) 32.8 g C ) 49.1 g D ) 73.7 g 4) Calculate the number of moles of hydrogen gas that should be produced from the complete reaction of 3.93g of zinc metal. Zn (s) + 2HCl (aq) = H 2(g) + ZnCl 2(aq) A ) mol B ) 3.93 mol C ) 16.6 mol D ) 257 mol

Gravimetric Stoichiometry 3) What mass of aluminum oxide can be produced from the complete reaction of mol of oxygen gas? 4Al (s) + 3O (g) = 2Al 3 O 2 A ) 13.8 g B ) 32.8 g C ) 49.1 g D ) 73.7 g 4) Calculate the number of moles of hydrogen gas that should be produced from the complete reaction of 3.93g of zinc metal. Zn (s) + 2HCl (aq) = H 2(g) + ZnCl 2(aq) A ) mol B ) 3.93 mol C ) 16.6 mol D ) 257 mol

Gravimetric Stoichiometry 3) What mass of aluminum oxide can be produced from the complete reaction of mol of oxygen gas? 4Al (s) + 3O (g) = 2Al 3 O 2 A ) 13.8 g B ) 32.8 g C ) 49.1 g D ) 73.7 g 4) Calculate the number of moles of hydrogen gas that should be produced from the complete reaction of 3.93g of zinc metal. Zn (s) + 2HCl (aq) = H 2(g) + ZnCl 2(aq) A ) mol B ) 3.93 mol C ) 16.6 mol D ) 257 mol

Gravimetric Stoichiometry Use the following information to answer questions # 5-7: The Chemistry recipe for S’mores is : 2 graham crackers + 4 marshmallows + 3 pieces of chocolate →1 S’more You have the following supplies in your pantry: 50 graham crackers, 80 marshmallows, 65 pieces of chocolate. 5. What is limiting reactant? A. The graham crackers B. The marshmallows C. The pieces of chocolate. D. Chocolate and the graham crackers both limit the amount of S’mores 6. How many S’mores can you make? A. 25 B. 21 C. 20 D If you borrowed 10 graham crackers, 20 marshmallows, and 4 pieces of chocolate from your neighbor, and added these to your original amount, how many total S’mores could you make? A. 30 B. 25 C. 23 D. 78

Gravimetric Stoichiometry Use the following information to answer questions # 5-7: The Chemistry recipe for S’mores is : 2 graham crackers + 4 marshmallows + 3 pieces of chocolate →1 S’more You have the following supplies in your pantry: 50 graham crackers, 80 marshmallows, 65 pieces of chocolate. 5. What is limiting reactant? A. The graham crackers B. The marshmallows C. The pieces of chocolate. D. Chocolate and the graham crackers both limit the amount of S’mores 6. How many S’mores can you make? A. 25 B. 21 C. 20 D If you borrowed 10 graham crackers, 20 marshmallows, and 4 pieces of chocolate from your neighbor, and added these to your original amount, how many total S’mores could you make? A. 30 B. 25 C. 23 D. 78

Gravimetric Stoichiometry Use the following information to answer questions # 5-7: The Chemistry recipe for S’mores is : 2 graham crackers + 4 marshmallows + 3 pieces of chocolate →1 S’more You have the following supplies in your pantry: 50 graham crackers, 80 marshmallows, 65 pieces of chocolate. 5. What is limiting reactant? A. The graham crackers B. The marshmallows C. The pieces of chocolate. D. Chocolate and the graham crackers both limit the amount of S’mores 6. How many S’mores can you make? A. 25 B. 21 C. 20 D If you borrowed 10 graham crackers, 20 marshmallows, and 4 pieces of chocolate from your neighbor, and added these to your original amount, how many total S’mores could you make? A. 30 B. 25 C. 23 D. 78

Gravimetric Stoichiometry Use the following information to answer questions # 5-7: The Chemistry recipe for S’mores is : 2 graham crackers + 4 marshmallows + 3 pieces of chocolate →1 S’more You have the following supplies in your pantry: 50 graham crackers, 80 marshmallows, 65 pieces of chocolate. 5. What is limiting reactant? A. The graham crackers B. The marshmallows C. The pieces of chocolate. D. Chocolate and the graham crackers both limit the amount of S’mores 6. How many S’mores can you make? A. 25 B. 21 C. 20 D If you borrowed 10 graham crackers, 20 marshmallows, and 4 pieces of chocolate from your neighbor, and added these to your original amount, how many total S’mores could you make? A. 30 B. 25 C. 23 D. 78 *questions from

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