Law of conservation of mass

Front

After combining a reactant with a mass of 7g and another with a mass of 3g in a sealed container, predict the total mass of the products.

Back

10g

Front

In a sealed container, Alice combines a reactant with a mass of 20 grams with another reactant with a mass of 16 grams. After the reaction, what is the most reasonable prediction Alice can make for the total mass of the products of this reaction?

Back

36g

Front

According to the law of conservation of mass, mass is neither created nor destroyed in any ordinary chemical reaction. Which of the following is a demonstration of this law?

• When hydrogen and oxygen combine to make water, oxygen atoms are converted to hydrogen atoms.
• When sodium and chlorine combine to make salt, some of the sodium is always lost.
• When water breaks down into hydrogen and oxygen, the number of atoms always remains the same.
• When iron reacts with oxygen to form rust, the mass of the iron atoms increases.

Back

When water breaks down into hydrogen and oxygen, the number of atoms always remains the same.

Front

Total mass of products when reactants are 27g and 24g in a sealed container?

Back

51g

Front

After combining reactants with masses of 6g and 18g in a sealed container, predict the total mass of the products.

Back

24g

Front

Which of the following is true regarding the atoms involved in a chemical reaction?

• The same number of each type of atom will always be present before and after a chemical reaction takes place.
• Some of the atoms present before the reaction will always be lost during a chemical reaction.
• Some of the atoms will always be changed into a different type of atom by a chemical reaction.
• During a chemical reaction, atoms will always be combined into much larger molecules.

Back

The same number of each type of atom will always be present before and after a chemical reaction takes place.

Front

Which chemical formula correctly demonstrates the law of conservation of mass?

Back

Front

What is the difference between a coefficient and a subscript in a chemical formula?

Back

A coefficient tells you how many molecules there are in a chemical formula while a subscript tells you how many atoms there are in a chemical formula.

Front

The law of conservation of mass states...

Back

Matter can neither be created nor destroyed. The mass of all the reactants must equal the mass of all the products.