Limiting Reactants and Stoichiometry

The video tutorial covers heat stoichiometry, focusing on energy exchange in chemical reactions. It explains enthalpy (Delta H) and differentiates between exothermic and endothermic reactions. The tutorial includes solving stoichiometry problems involving sodium, calculating energy release, and addressing limiting reactants with sodium and water.

What is the primary focus of heat stoichiometry?

• Calculating the mass of reactants

• Determining the energy exchange in reactions

• Identifying the color change in reactions

• Measuring the volume of gases produced

What does a negative Delta H value indicate about a reaction?

• The reaction is exothermic

• The reaction does not involve energy exchange

• The reaction is endothermic

• The reaction is at equilibrium

How is the molar mass of sodium used in stoichiometry calculations?

• To measure the temperature change

• To convert grams of sodium to moles

• To determine the color of sodium

• To calculate the volume of sodium

What is the energy released when 13 grams of sodium is used in the reaction?

• -103.9 kJ

• -104 kJ

• -100 kJ

• -110 kJ

What is the significance of significant figures in stoichiometry calculations?

• They calculate the volume of gases

• They measure the temperature change

• They ensure precision in calculations

• They determine the color of the solution

What is a limiting reactant?

• A reactant that speeds up the reaction

• A reactant that does not participate in the reaction

• A reactant that limits the amount of product formed

• A reactant that is in excess

How many moles of sodium are equivalent to 10 grams of sodium?

• 0.5 moles

• 0.43 moles

• 0.25 moles

• 0.35 moles

In the given problem, which reactant is the limiting reactant?

• Hydrogen

• Sodium hydroxide

• Water

• Sodium

What is the energy released when 10 grams of sodium reacts with 17 grams of water?

• -160 kJ

• -190 kJ

• -173 kJ

• -184 kJ

Why is it important to identify the limiting reactant in a reaction?

• To determine the color of the product

• To calculate the maximum amount of product formed

• To measure the temperature change

• To find the pH of the solution