Limiting Reactants and Stoichiometry

The video tutorial covers stoichiometry calculations focusing on limiting reactants. It explains when a chemical reaction stops, defines limiting and excess reactants, and introduces abbreviations for them. The tutorial uses a BCA table to solve an example problem involving sulfur and chlorine, converting grams to moles and determining the limiting reactant. It concludes with calculating the mass of the product formed and the excess reactant remaining.

What is the term used for a reactant that is completely consumed in a chemical reaction?

• Product

• Limiting reactant

• Catalyst

• Excess reactant

Which abbreviation is used for an excess reactant?

• EX

• XS

• ER

• LR

Why is it important to identify the limiting reactant in stoichiometry problems?

• To measure the pressure in the reaction

• To find the temperature of the reaction

• To calculate the amount of product formed

• To determine the reaction speed

What is the first step in using the BCA table method for stoichiometry problems?

• Calculate the reaction yield

• Determine the reaction temperature

• Convert grams to moles

• Identify the limiting reactant

In the example problem, what is the molar mass of one sulfur atom?

• 32.07 grams

• 35.45 grams

• 256.56 grams

• 70.90 grams

How many moles of chlorine are needed to react with all the sulfur in the example problem?

• 1.4104 moles

• 3.118 moles

• 2.000 moles

• 0.7795 moles

What is the limiting reactant in the example problem involving sulfur and chlorine?

• Both sulfur and chlorine

• S2Cl2

• Chlorine

• Sulfur

What is the mass of the S2Cl2 product formed in the example problem?

• 109.5 grams

• 190.4 grams

• 256.56 grams

• 135.04 grams

How much excess sulfur is left after the reaction in the example problem?

• 109.5 grams

• 1.4104 moles

• 190.4 grams

• 0.4270 moles

What is the purpose of using molar mass in the final calculations of the example problem?

• To determine the reaction speed

• To convert moles to grams

• To measure the pressure in the reaction

• To find the reaction temperature