Transcript Document

Solving Stoichiometry Problems
Objectives:
• 1. Name four major categories of
stoichiometry problems.
• 2. Explain how to solve each type of
stoichiometry problems.
Mole-Mole Problems
Problem: How many moles of HCl are needed to react with 0.87 moles
of Al?
• Step 1: Balance The Equation
• Step 2: Set up the equation identifying the given and the want
0.87 mol Al
HCl
Al
• Step 3: Calculate the new moles using the ratios of coefficients from the
balanced equation
0.87 mol Al
6 HCl
2 Al
= 2.6 mol HCl
Mass-Mass Problems
(MassgMol; MolgMol; MolgMass)
Problem: How many grams of Al can be created decomposing 9.8g of Al2O3?
• Step 1: Balance The Equation
• Step 2: Calculate the moles of the given (mol/g)
• Step 3: Calculate the moles of the new substance using the
molar ratios
• Step 4: Calculate the new mass using the new moles
Solutions to Common Problems
particles
particles
/
mass
6.02x1023
Mole given
x
6.02x1023
New mole
using ratios
x molar mass
/ molar mass
volume
mass
/ 22.4L
Mole to mole using the ratio of coefficients
x 22.4L
volume