Conservation of Mass Flashcards

All 4 cards in this deck

State the law of conservation of mass.

No atoms are lost or made in a chemical reaction, so the total mass of the products equals the total mass of the reactants.

What happens to the balance reading when a precipitation reaction is carried out in a closed flask?

It stays the same — nothing is lost and nothing is gained.

Why does the mass increase when magnesium is burned in an open crucible?

Oxygen from the air combines with the magnesium and is added to its mass.

True or false? When a reaction in an open flask gives off a gas, mass has been destroyed.

False. The gas escapes into the air, so the flask weighs less, but the total mass is unchanged.