Chemical Reactions and Balancing Equations Quiz

What is the primary goal when counting atoms in a chemical equation?

• To calculate the molecular weight

• To find the number of molecules

• To identify the elements present

• To determine if the equation is balanced

What does a subscript in a chemical formula indicate?

• The charge of the element

• The number of molecules

• The type of bond present

• The number of atoms of an element

If there is no subscript next to an element in a chemical formula, what does it imply?

• The element is a gas

• The element is not part of the compound

• There is one atom of that element

• There are no atoms of that element

What is the significance of the prefix 'sub' in the term 'subscript'?

• It means beside

• It means below

• It means within

• It means above

In the chemical equation FES2 + O2 → Fe2O3 + SO2, how many sulfur atoms are present in the reactants?

• Four

• Two

• One

• Three

Why is the equation FES2 + O2 → Fe2O3 + SO2 not balanced?

• There are more iron atoms in the products

• There are more sulfur atoms in the reactants

• There are fewer oxygen atoms in the reactants

• There are more oxygen atoms in the products

Which of the following is a product in the equation FES2 + O2 → Fe2O3 + SO2?

• FES2

• S2

• Fe2O3

• O2

In the example of carbon and oxygen forming carbon monoxide, why is this equation considered balanced?

• The number of carbon atoms is equal on both sides

• The number of oxygen atoms is equal on both sides

• Both carbon and oxygen atoms are equal on both sides

• The equation is not balanced

What does the law of conservation of mass state?

• Mass can be created or destroyed

• Mass is always conserved in physical changes only

• Mass of reactants must equal mass of products

• Mass is irrelevant in chemical reactions

What should you do if there is no visible number next to an element in a chemical formula?

• Assume there are two atoms

• Assume there is one atom

• Assume there are zero atoms

• Assume the element is not present