Which procedure could be used to demonstrate that matter is conserved during a chemical change or reaction?

Question

1. Find the mass of a stick of butter. Heat the butter until it melts. Find the mass of the melted butter.
2. Find the mass of a log. Burn the log until it turns to ash and smoke. Find the mass of the ash.
3. Find the mass of an acid and a base. Combine them to produce water and a salt. Find the mass of the water and salt.
4. Find the mass of a piece of paper. Tear the paper into smaller pieces. Find the mass of the pieces.

Answer 1

To demonstrate that matter is conserved during a chemical change or reaction, the most appropriate procedure would be:

3. Find the mass of an acid and a base. Combine them to produce water and a salt. Find the mass of the water and salt.

This procedure involves a chemical reaction where the acid and base react to form new products (water and salt). According to the law of conservation of mass, the mass of the reactants (acid and base) will equal the mass of the products (water and salt). This method effectively showcases the concept of mass conservation during a chemical change.

The other options either do not involve a true chemical reaction (like simply melting or tearing), or they do not account for all products of a chemical reaction (as in burning the log, where some mass is lost as smoke and gases).