Limiting Reactants and Enthalpy Changes

This video tutorial covers enthalpy changes of reactions in solutions, focusing on specific heat, limiting reactants, and balanced equations. It includes an example problem involving silver nitrate and HCl, demonstrating how to calculate Delta H using given concentrations, volumes, and temperature changes. The tutorial emphasizes understanding the relationship between specific heat, temperature change, and mass to find the heat of the solution and the enthalpy of reaction.

What is the main focus of the video on enthalpy changes in solution?

• Balanced equations and limiting reactants

• Specific heat problems

• Enthalpies of combustion

• Molar mass calculations

Which of the following is NOT a component of the Delta H formula discussed?

• Mass

• Specific heat

• Change in temperature

• Volume

In the example problem, what are the two reactants mixed in the calorimeter?

• Silver nitrate and HCl

• Silver chloride and nitric acid

• Water and ethanol

• Sodium chloride and water

What is the initial temperature of the mixture in the example problem?

• 23.1 degrees Celsius

• 22.3 degrees Celsius

• 25.0 degrees Celsius

• 20.0 degrees Celsius

How is the number of moles calculated in the example problem?

• By dividing mass by molar mass

• By measuring the temperature change

• By multiplying concentration by volume

• By using Avogadro's number

What is the limiting reactant in the example problem?

• Neither is limiting

• Both are limiting

• Silver nitrate

• HCl

What is the specific heat value used for the solution in the example problem?

• 2.18 joules per gram degree Celsius

• 3.18 joules per gram degree Celsius

• 4.18 joules per gram degree Celsius

• 5.18 joules per gram degree Celsius

What is the calculated heat of the solution in joules?

• 340 joules

• 240 joules

• 440 joules

• 540 joules

What is the final Delta H of reaction in kilojoules per mole?

• -58 kilojoules per mole

• -78 kilojoules per mole

• -34 kilojoules per mole

• -68 kilojoules per mole

What is the main difference in solving for moles in this problem compared to previous ones?

• Using grams instead of concentration

• Using concentration instead of grams

• Using temperature instead of volume

• Using pressure instead of mass