Chemical Reactions Quiz

What does a chemical reaction involve?

• Breaking down molecules

• Rearranging atoms in the reactants to form products

• Creating new elements

What does the law of conservation of mass state?

• Atoms are created during a chemical reaction

• The total mass of the reactants is equal to the total mass of the products

• Mass is lost during a chemical reaction

How can we represent the law of conservation of mass using an equation?

• Mass of the products > Mass of the reactants

• Mass of the products = Mass of the reactants

• Mass of the products < Mass of the reactants

Give an example when the products appear to have lost mass.

• When a solid precipitates out of a solution

• When a gas is released and escapes from the reaction mixture

• When a liquid evaporates during a reaction

What needs to be done when balancing equations?

• Increase the number of atoms in the products

• Decrease the number of atoms in the reactants

• Ensure the number of atoms in the reactants equals the number of atoms in the products

Which number in the periodic table is the relative atomic mass when taking into account all the isotopes on Earth?

• The atomic number

• The mass number

• The relative atomic mass (Ar)

What is the relative formula mass (Mr) of a compound?

• The sum of all the masses of the atoms in the compound

• The sum of all the relative atomic masses of the atoms in the compound

• The mass of the compound divided by the number of atoms

What is the value for Avogadro's constant?

• 6.02x10^23

• 1.00x10^23

• 6.02x10^24

What are chemical amounts measured in?

• Grams

• Moles

• Liters

What is the symbol for the unit mole?

• M

• Mo

• Mol