Crucible Experiment Procedures and Safety

Mr. Zorin guides students through a stoichiometry lab focused on the thermal decomposition of sodium bicarbonate. The lab involves measuring sodium bicarbonate, preparing and heating a crucible, and analyzing the results using stoichiometry to determine the correct chemical reaction. Safety precautions and accurate measurements are emphasized throughout the process.

What is the main objective of the stoichiometry lab?

• To measure the boiling point of sodium bicarbonate

• To determine the correct chemical reaction for the thermal decomposition of sodium bicarbonate

• To calculate the density of sodium bicarbonate

• To find the melting point of sodium bicarbonate

What is the first step in preparing the crucible for the experiment?

• Weighing the crucible

• Filling the crucible with sodium bicarbonate

• Cleaning the crucible with a paper towel

• Heating the crucible

Why is it important to inspect the Bunsen burner hose before use?

• To verify it is the right color

• To confirm it is made of rubber

• To check for cracks that could lead to leaks and fires

• To ensure it is the correct length

How far should the Bunsen burner flame be from the crucible?

• Directly touching the crucible

• About 5 inches away

• About 10 inches away

• About 2 to 3 inches away

What is the role of the clay triangle in the experiment?

• To mix the reactants

• To cool the crucible

• To support the crucible during heating

• To measure the temperature

What should you do if the flame is not reaching the crucible?

• Turn up the gas valve

• Move the crucible closer

• Use a larger Bunsen burner

• Add more sodium bicarbonate

What should you do if the crucible is still radiating heat after cooling?

• Immediately weigh it

• Use your fingers to check the temperature

• Give it more time to cool

• Place it in cold water

What is the final step after cooling the crucible?

• Cleaning the crucible

• Heating it again

• Weighing the crucible and product

• Adding more sodium bicarbonate

What is the purpose of calculating the percent yield in this experiment?

• To find the volume of gas produced

• To measure the temperature change

• To evaluate the efficiency of the chemical reaction

• To determine the purity of sodium bicarbonate

Which of the following is ignored in the stoichiometry calculations for this lab?

• The solid product

• The gas products

• The initial mass of sodium bicarbonate

• The mass of the crucible