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Flashcards in C3 Deck (10)
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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