Which procedure could be used to demonstrate that matter is conserved during a chemical change or reaction?(1 point)

Question

Responses

Find the mass of a stick of butter. Heat the butter until it melts. Find the mass of the melted butter.
Find the mass of a stick of butter. Heat the butter until it melts. Find the mass of the melted butter.

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.
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.

Find the mass of a piece of paper. Tear the paper into smaller pieces. Find the mass of the pieces.
Find the mass of a piece of paper. Tear the paper into smaller pieces. Find the mass of the pieces.

Find the mass of a log. Burn the log until it turns to ash and smoke. Find the mass of the ash.

Answer 1

To demonstrate that matter is conserved during a chemical change or reaction, the best procedure among the options provided is:

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 reactants (acid and base) are transformed into products (water and salt), and it allows for the measurement of total mass before and after the reaction to show that matter is conserved. The other options either involve physical changes or do not adequately demonstrate the conservation of mass in a chemical reaction.

Answer 2

What is always true according to the Law of Conservation of Matter?(1 point)
Responses

New molecules cannot be formed from the reactants during a chemical reaction.
New molecules cannot be formed from the reactants during a chemical reaction.

The total number of molecules before and after a chemical reaction stays the same.
The total number of molecules before and after a chemical reaction stays the same.

Atoms can be rearranged during a chemical reaction but cannot be added or taken away.
Atoms can be rearranged during a chemical reaction but cannot be added or taken away.

Atoms created during a chemical reaction must have the same mass as the atoms in the reactants.

Answer 3

The statement that is always true according to the Law of Conservation of Matter is:

Atoms can be rearranged during a chemical reaction but cannot be added or taken away.

This principle emphasizes that in a chemical reaction, the total number of atoms remains constant; they are simply rearranged to form new molecules without any atoms disappearing or being created.

Answer 4

A student combines two liquids in a beaker. She observes that the mass of the combined liquid is less than the mass of the two separate liquids. The student claims that this observation shows that matter is not conserved in chemical reactions. Which statement explains why the student’s claim is incorrect?(1 point)
Responses

The reaction produced a gas that escaped the beaker.
The reaction produced a gas that escaped the beaker.

The reaction did not change the physical properties of the liquids.
The reaction did not change the physical properties of the liquids.

The product contained fewer atoms than the reactants.
The product contained fewer atoms than the reactants.

The combined liquid was warmer than the two separate liquids.

Answer 5

The statement that explains why the student’s claim is incorrect is:

The reaction produced a gas that escaped the beaker.

This indicates that some of the matter (in the form of gas) left the system, which would result in a lower measured mass of the combined liquids compared to the mass of the two separate liquids. This does not mean that matter is not conserved; rather, it implies that not all of the matter was contained within the beaker during the reaction.