Limiting Reactants and Chemical Formulas

This video tutorial explains how to find the mass of the excess reactant remaining after a chemical reaction. It is divided into three main parts: identifying the limiting reactant, calculating the grams of excess reactant consumed, and determining the mass of the excess reactant left. The tutorial includes balancing chemical equations and provides a practice problem involving aluminum and sulfur to reinforce the concepts.

What is the first step in determining the mass of the excess reactant after a reaction?

• Identify the limiting reactant

• Calculate the molar mass of the products

• Measure the temperature change

• Determine the volume of the solution

What is the chemical formula for aluminum sulfate?

• Al(SO4)2

• Al2(SO4)3

• Al2SO4

• Al3(SO4)2

How do you determine the limiting reactant in a chemical reaction?

• By comparing the initial masses of reactants

• By calculating the mole-to-coefficient ratio

• By measuring the final temperature

• By observing the color change

What is the next step after identifying the limiting reactant?

• Find the amount of excess reactant consumed

• Measure the pressure of the system

• Determine the pH of the solution

• Calculate the total mass of products

If 7.33 g of aluminum is consumed, how much aluminum remains after the reaction?

• 80 g

• 72.67 g

• 0 g

• 7.33 g

In the practice problem, what is the chemical formula for aluminum sulfide?

• AlS

• Al3S2

• AlS2

• Al2S3

How many sulfur atoms are needed to balance the equation for aluminum sulfide?

• 32

• 24

• 16

• 8

What is the limiting reactant in the reaction between aluminum and sulfur?

• Aluminum sulfide

• Sulfur

• Aluminum

• Hydrogen gas

How do you calculate the grams of excess reactant consumed?

• By using the initial mass of the limiting reactant

• By observing the color change

• By converting moles of limiting reactant to grams of excess reactant

• By measuring the final volume of the solution

What is the mass of excess aluminum remaining after the reaction with sulfur?

• 0 g

• 10.74 g

• 39.2 g

• 50 g