C3 Flashcards
(10 cards)
What is the law of conservation of mass?
No atoms are lost or made during a chemical reaction. This means the mass of the products equals the mass of the reactants.
Define relative atomic mass (Ar).
The mass of an atom compared to 1/12 of the mass of a carbon 12 atom.
Define relative formula mass (Mr).
The sum of the relative atomic masses in a compound.
Some chemical reactions seem to involve a change in mass. How can this be explained?
One or more of the reactants or products is a gas. The mass or gas is often not measured.
What is a limiting reagent?
Chemical used up in a reaction that limits the amount of product formed.
What is one mole of particles?
The Avagadro constant (6.02 x 10 to the power of 23 particals).
What is the formula to calculate moles?
Moles = mass/relative formula mass
What is concentration?
The amount of chemical dissolved in a certain volume of solution.
What unit do we use for concentration?
g dm-3 (grams per decimetre cubed)
What is the formula used to calculate concentration?
Concentration = mass of solute/volume
