Conservation of Mass

How is the Law of Conservation of Matter best represented in a chemical reaction?

• The mass of the products is greater than the mass of the reactants.

• The mass of the reactants is greater than the mass of the products.

• The mass of the reactants is equivalent to the mass of the products.

• The mass of the reactants has no relationship to the mass of the products.

The mass of chemical A is 2 g, and the mass of chemical B is 5 g. If the two chemicals are mixed together and a chemical reaction takes place, what is the mass of the end products?

• 2 g

• 3 g

• 7 g

• 10 g

Which chemical equation supports the Law of Conservation of Matter?

• 2H + O2 → 2H2O

• H2 + O2 → H2O

• H2 + O2 → 2H2O

• 2H2 + O2 → 2H2O

Alexandra is performing this combustion reaction in lab: C3H8 + 5O2 → 3CO2 + 4H2O. If she carefully measures out 220 g of C3H8 and discovers that she has produced 660 grams of carbon dioxide and 360 g of water, how many grams of oxygen must have been required to react with the C3H8?

• 220 g

• 580 g

• 800 g

• 1,240 g

Which chemical equation is balanced to show that mass is conserved during a chemical reaction?

• H2 + Cl2 → HCl

• H2 + O2 → H2O

• H2 + Cl2 → 2HCl

• H2 + O2 → 2H2O

How does a chemical equations support the law of conservation of matter?

• The left must be greater than the right.

• The right must be greater than the left.

• Both sides must have the same number of atoms.

• Both sides must have the same atoms and number of each atom.

A student mixes 8 grams of Chemical A with 6 grams of Mixture B in a closed container. The chemicals react completely and the products are formed.

According to the Law of Conservation of Mass, what should be the mass of the products formed?

• 2 grams

• 6 grams

• 8 grams

• 14 grams

Which chemical equation is balanced to show that matter is conserved in a chemical reaction?

• CaCO3 → CaCO2 + CO2

• C + H2O → CO + H2

• N2 + 3H2 → 3NH3

• SO2 + O2 → 2SO4

In the reaction, 30 g of a solid reacts with 12 g of a liquid to produce a gas and a compound with a mass of 10 g. Which value most accurately shows the mass of the gas produced?

• 10 g

• 12 g

• 30 g

• 32 g

What is the number of hydrogen atoms on the reactant side?

• 2

• 6

• 10

• 12