Suppose 10 atoms of carbon (C) react with 20 atoms of oxygen (O) to form 10 molecules of carbon dioxide ( CO2 ). According to the law of conservation of matter, how many atoms are present in this reaction?(1 point)

Question

Suppose 10 atoms of carbon (C) react with 20 atoms of oxygen (O) to form 10 molecules of carbon dioxide ( CO2 ). According to the law of conservation of matter, how many atoms are present in this reaction?(1 point)
Responses

30
30

20
20

15
15

10

GPT-4o mini · Answer

To determine the total number of atoms present in the reaction, you can count the atoms of each element on both the reactant and product sides.

In the given reaction:

Reactants: 10 atoms of carbon (C) and 20 atoms of oxygen (O)
Products: 10 molecules of carbon dioxide (CO₂), which contains 10 atoms of carbon and 20 atoms of oxygen (since each CO₂ molecule has 1 carbon atom and 2 oxygen atoms: 10 CO₂ has 10 C and 20 O).

Now, let's count the total number of atoms:

Reactants:

Carbon: 10 atoms
Oxygen: 20 atoms
Total = 10 C + 20 O = 30 atoms

Products:

Carbon: 10 atoms (from 10 CO₂)
Oxygen: 20 atoms (from 10 CO₂)
Total = 10 C + 20 O = 30 atoms

Thus, according to the law of conservation of matter, the total number of atoms in this reaction is consistent on both sides, and there are 30 atoms present in the reaction.

Answer: 30

Daphne · Answer

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

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

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.

GPT-4o mini · Answer

The best procedure to demonstrate that matter is conserved during a chemical change or reaction 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 specifically involves a chemical reaction (neutralization reaction between the acid and base) and allows you to measure the total mass before and after the reaction. According to the law of conservation of mass, the total mass of the reactants should equal the total mass of the products, therefore demonstrating that matter is conserved.

The other options involve physical changes or incomplete reactions where gas may escape, which would not adequately demonstrate the conservation of matter in a chemical change.

Daphne · Answer

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

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

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

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.

GPT-4o mini · Answer

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 means that during a chemical reaction, the atoms present in the reactants are rearranged to form products, but the total number of atoms remains the same. Matter cannot be created or destroyed, only transformed, which aligns with this principle.

The other statements provided are not entirely accurate according to the law. For example, while the number of reactant atoms remains equal to the number of product atoms, the total number of molecules does not necessarily stay the same, and new molecules can indeed be formed during a reaction.

Daphne · Answer

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

The combined liquid was warmer than the two separate liquids.

GPT-4o mini · Answer

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

The reaction produced a gas that escaped the beaker.

In this situation, if gas is produced during the mixing of the two liquids and it escapes into the air, the mass of the remaining combined liquids in the beaker would be less than the sum of the masses of the two separate liquids. This does not mean that matter is not conserved; rather, it indicates that some of the matter (in the form of gas) left the system. According to the Law of Conservation of Matter, the total mass of all matter before and after a reaction is conserved, but it must be accounted for in the same system. If some gas escapes the beaker, it is no longer included in the mass measurement, leading to the observed discrepancy.