IIT/JEE Chemistry Practice #2: Molar Mass/Stoichiometry

Dave explains two practice problems involving molar mass and stoichiometry. The first problem requires converting molecules of copper sulfate pentahydrate to moles using Avogadro's number and then calculating the mass. The second problem involves determining how many grams of oxygen will react with aluminum by forming and balancing a chemical equation, then using stoichiometric ratios to find the answer.

What is the mass of 1 * 10 to the 22 molecules of copper sulfate pentahydrate?

Explain how to convert molecules to moles using Avogadro's number.

What is the molar mass of copper sulfate pentahydrate?

How many grams of oxygen will react completely with 27 grams of aluminum?

Describe the process of balancing the chemical equation for the reaction between aluminum and oxygen.

What stoichiometric ratio is used to determine the amount of oxygen needed for the reaction with aluminum?

Calculate the grams of O2 produced from 27 grams of aluminum based on the stoichiometric calculations.