userdata-paziras-Chem51-Chap_06

# Howmany mo lesoffe3o4

This preview shows page 1. Sign up to view the full content.

This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: ­Mass Calculations: · Relates mass of reactants and products in a balanced chemical equat ion Examples: 1. What mass of oxygen will be required to react completely with 96.1 g of propane, C3H8, according to the equation below? 1 C3H8 (g) + 5 O2 (g) 3 CO2 (g) + 4 H2O (g) 1 mo l C3H8 5 mo l O2 32.0 g O2 96.1 g C3H8 x ¾¾¾¾¾ x ¾¾¾¾¾ x ¾¾¾¾¾ = 349 g O2 44.1 g C3H8 1 mo l C3H8 1 mo l O2 Molar Mass Mole Ratio Molar Mass 2. What mass of carbon dio xide will be produced from the react ion of 175 g of propane, as shown above? 175 g C3H8 x ¾¾¾¾¾¾¾ x ¾¾¾¾¾¾¾ x ¾¾¾¾¾¾¾ = g CO2 23 Chemistry 51 Chapter 6 LIMITING REACTANT · When 2 or more reactants are combined in non­stoichiometric ratios, the amount of product produced is limited by the reactant that is not in excess. · This reactant is referred to as limiting reactant. · When do ing stoichio metric problems o f this type, the limit ing reactant must be determined first before proceeding wit h the calculat ions. Analogy: The number of sundaes possible is limited by the amount of syrup, the limiting reactant. · When so lving limit ing reactant problems, assume each reactant is limit ing reactant and calculate the desired quantit y based on that assumpt ion. · Compare your answers for each assumpt ion; the lower value is the correct assumpt ion. 24 Chemistry 51 Chapter 6 LIMITING REACTANT Examples: 1. How many mo les of H2O can be produced by reacting 4.0 mo l of hydrogen and 3.0 mo l of oxygen gases as shown below: 2 H2 (g) + 1 O2 (g) 2 H2O (g) Assume hydrogen is the limit ing reactant: 4.0 mo l H2 x ¾¾¾¾¾¾¾¾ = mol H2O Assume oxygen is the limit ing reactant: 3.0 mo l O2 x ¾¾¾¾¾¾¾¾ = mol H2O Correct limit ing reactant is _________ and __________ mo l of H2O are produced. 25 Chemistry 51 Chapter 6 2. A fuel mixture used in the early days o f rocketry was a mixture of N2H4 and N2O4, as shown below. How many grams of N2 gas is produced when 100 g of N2H4 and 200 g of N2O4 are mixed...
View Full Document

{[ snackBarMessage ]}

Ask a homework question - tutors are online