cons of mass

• Conservation of mass


  In a chemical reaction, mass is always conserved - no atoms are created or destroyed, only the bonds between atoms change
• Balancing a chemical equation

  1. Ensure the total relative formula masses on each side are equal

  2. Ensure the number of atoms of each element is the same on each side
• Reactants have a certain mass


  Products have the same total mass
• When a reaction involves a gas, the mass may appear to change because the gas can come from or float off into the air and not be measured
• Doing the experiment in a sealed container

  Ensures all gases are trapped and the total mass is accounted for
• Doing experiments in a sealed container avoids issues with gases affecting the measured mass
• Mass is always conserved in a chemical reaction, regardless of whether the mass is measured in grams or by counting atoms
• • If the mass appears to increase, it's likely because a reactant is a gas
  • If the mass appears to decrease, it's likely because a product is a gas