2. Law of Conservation of Mass & Law of Constant Proportions

What does the Law of Conservation of Mass state?

Mass cannot be created or destroyed in a closed system during chemical reactions or physical changes. (Mass of reactants = Mass of products)

Who formulated the Law of Conservation of Mass?

Antoine Lavoisier

What is a key application of the Law of Conservation of Mass?

Balancing chemical equations to ensure mass is conserved.

What happens in nuclear reactions regarding mass and the Law of Conservation of Mass?

Mass can be converted into energy (E=mc²), so the law is adjusted for energy-mass equivalence.

What does the Law of Constant Proportions state?

A chemical compound always contains its elements in fixed mass ratios, regardless of quantity or source.

Who established the Law of Constant Proportions?

Joseph Proust

How can you express the Law of Constant Proportions mathematically?

Mass of A/Mass of B​=Constant

What is an example of the Law of Constant Proportions in a compound?

Water (H₂O) always has hydrogen and oxygen in a 2:1 mass ratio.

Does the Law of Constant Proportions apply to mixtures?

No, it applies only to compounds, not to mixtures where component proportions can vary.