Test Conservation of mass Flashcards
Total mass of ALL reactants ( total mr) =
= total mass of ALL products ( total mr )
What is conservation of mass
In a reaction no atoms are Created or destroyed. There are the same number and types of atom on each side of the equation. No mass is gained or lost, mass is conserved
How would u show mass is conserved in a reaction when given a balanced symbol equation
Add up the masses of the reactants taking into account big and little numbers and show that equals the mass of the products
Why would the mass of a reaction may seem to change
Because a gas is involved and the reaction is taking place in an unsealed reaction vessel
Why would the mass seem to increase
Because one of the reaction is a gas. This means that before the reaction the gas is not contained in the vessel so it mass cant be included in the total mass. After the reaction it becomes part of the product and the mass is now part of the total mass so the mass SEEMS to increase.
Exsample of when a mass seems to increase
When a metal reacts with oxygen. Before the reaction only the mass of the metal is measured . After the reaction the mass of the metal oxide is measured so it SEEMS to increase
Why would the mass seem to decrease
Because one of the products is a gas. Before the reaction all the reactants masses are all measured. After the reaction the products which are gases escape into the atmosphere do the mass SEEMS to decrease
Example for when a mass seems to decrease
When a metal carbonate thermally decomposes ( breaks down with heat )to form a metal oxide and co2 gas.The co2 escapes into the atmosphere because the vessel is not sealed and the mass SEEMS to decrease
