Chemical Reactions and Mass Conservation

In this video tutorial, the teacher and assistant Lizzy conduct Activity 1222, focusing on a chemical reaction in a closed system. They begin by setting up materials, including Seltzer tablets and a bottle with water. Initial masses are measured, and the experiment is conducted by quickly sealing the bottle to capture gases. Observations are made regarding temperature and gas release, indicating a chemical reaction. Final measurements confirm the conservation of mass, and the activity concludes with a discussion on the irreversibility of the reaction.

What is the main difference in this experiment compared to the previous one?

• Using a closed system

• Using a different type of tablet

• Using a larger bottle

• Using more water

What is the initial mass of the cup and Seltzer tablet?

• 25.7 grams

• 67.4 grams

• 34.1 grams

• 59.0 grams

Why is it important to cap the bottle quickly during the experiment?

• To capture the gases released

• To prevent water from spilling

• To avoid breaking the bottle

• To keep the temperature constant

What observation indicates that a gas is being released during the reaction?

• The bottle emits a sound

• The bottle becomes heavier

• The bottle changes color

• The bottle expands and becomes rigid

Which of the following is NOT a sign of a chemical reaction observed in the experiment?

• Temperature change

• Gas release

• Bubbling

• Irreversibility

What is the final mass of the bottle, cap, water, and tablets?

• 59.0 grams

• 67.4 grams

• 34.1 grams

• 25.7 grams

What does the final mass measurement demonstrate about the experiment?

• Mass was irrelevant

• Mass was conserved

• Mass was gained during the reaction

• Mass was lost during the reaction

Why can't the reaction be reversed to get the original Seltzer tablets back?

• The reaction is chemical and irreversible

• The tablets dissolve completely

• The water evaporates

• The bottle is sealed

What is the total mass of the system at the start of the experiment?

• 93.1 grams

• 34.1 grams

• 67.4 grams

• 59.0 grams

What safety equipment is mentioned for the cleanup process?

• Apron

• Goggles

• Gloves

• Mask