Mass to Mass conversions

• Mass to mass problems involve one addition conversion

Example:

•  Lead (IV) Nitrate reacts with 5.O grams of Potassium Iodide. How many grams of Lead (IV) Nitrate are required for a complet reaction?
• Pb(NO3)4 + 4 KI---> 4 KNO3 + PbI4
• 5.0 g x 1 mol / 166 g x 1 / 4 x 455.2 g / 1 mol = 3.4 g

Example:

• How many grams of O2 are produced from the decomposition of 3.0 grams of Potassium Chlorate?
• 2 KClO3 ---> 2 K + Cl2 + 3 O2
• 3.0 g x 1mol / 106.6 g x 3 / 2 x 32 g / 1 mol = 1.4 g  

Example:

• When solid Zinc reacts with hydrochloric acid what mass of Hydrogen gas is produced when 2.5 grams of Zinc react?
• Zn + 2 HCl ---> H2 + ZnCl2 
• 2.5 g x 1 mol / 65.4 g x 1 / 1 x 2 g / 1 mol = 0.076 g 

Example:

• If 100 grams of Octane are burnt in a car engine what mass of Water is produced?
• C8H8 + 25 / 2 O2 ---> 9 H2O + 8 CO2 
• 100 g x 1 mol / 118 g x 9 / 1 x 18 g / 1 mol = 142 g 

-Eva