Quantative Chemistry Flashcards
What is the definition of relative atomic mass?
The average mass of all the isotopes of that element
What is the symbol for relative atomic mass?
Mr
What is the symbol for relative formula mass?
Ar
What does the law of conservation of mass state?
No atoms are lost or made during a chemical reaction
What is a chemical change?
A rearrangement of the atoms in the reactants, to form the products
In a chemical reaction, is there any change in the overall mass of the substances?
No
Why is it more difficult to measure the mass of a gas than the mass of a liquid or solid?
A gas can easily escape into the air
A chemical reaction is carried out in a beaker on a balance
Why may the balance reading for the products be less than the reading for the reactants?
- One of the products was a gas and floated off
- Some of the reactants may have been spilled
A chemical reaction is carried out in a beaker on a balance.
Why may the balance reading for the products be more than the reading for the reactants?
Gas from the air reacted with the reactants
The law of conservation states that the mass of reactants and products is a chemical reaction will be the same
In practice, the reading on a balance may change during a chemical reaction. Is this more likely in an open container or a sealed (closed) container?
Open container ~ the gases from the air can mix with the reactants or gaseous products can float off, thus changing the mass.
What is the formula for finding concentration from mass and volume?
Concentration = Mass
______
Volume
