Chemical Reactions and Heat Calculations

This video tutorial covers the enthalpy lab, focusing on writing balanced chemical equations with Delta H values. It explains a three-step problem-solving process involving moles, Q = MC delta T, and calculating Delta H. The video provides detailed walkthroughs of four lab examples, including reactions with iron, HCL, NaOH, H2O2, and NH4NO3. It also discusses potential sources of error and emphasizes the importance of converting results into kJ/mol.

What is the main objective of the enthalpy lab discussed in the video?

• To determine the pH of various solutions

• To measure the temperature change of water

• To write balanced chemical equations with Delta H

• To calculate the molarity of acids

In the first experiment, what was the role of iron?

• It was the limiting reactant

• It was not used in the experiment

• It was in excess

• It was a catalyst

What is the formula used to calculate the heat change in the experiments?

• Q = mCΔT

• Q = nRT

• Q = PΔV

• Q = ΔH - TΔS

In the second experiment, what is the product formed when HCl reacts with NaOH?

• NaCl and H2O

• H2 and NaCl

• NaOH and H2

• HCl and NaOH

What is the limiting reactant in the second experiment?

• Iron

• Water

• Sodium hydroxide

• Hydrochloric acid

What role does yeast play in the third experiment?

• It is not involved in the reaction

• It acts as a reactant

• It is a catalyst

• It is the limiting reactant

What is the main product formed when hydrogen peroxide decomposes in the presence of yeast?

• Water and oxygen gas

• Hydrogen gas

• Carbon dioxide

• Ammonia

In the final experiment, what is the initial mass of ammonium nitrate used?

• 5 grams

• 10 grams

• 15 grams

• 20 grams

What is a potential source of error mentioned in the video?

• Inaccurate molarity calculation

• Excessive stirring

• Heat absorption by the stirrer

• Incorrect pH measurement

What should be done with the final answers according to the video?

• Convert them to moles

• Convert them to kilojoules

• Convert them to grams

• Convert them to liters