# Percentage and formulae/ reversible reactions

• Created by: Leah
• Created on: 10-02-13 15:37
what can the relative atomic masses of the elements in a compound and its formula be used for?
to work out its percentage composition
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when can we calculate empirical formulae?
given the masses or percentage composition of elements present.
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what is the empirical formula?
the simplest ratio of the atoms or ions in a compound
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what is the empirical formula used for?
ionic compounds, but for covalent compounds it is not always the same as the molecular formula.
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how can we calculate the empirical formula of a compound from its percentage ratio of atoms?
divide the mass of each element in 100g of the compound by its Ar to give the ratio of atoms, then convert this to the simplest whole number ratio
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what happens in a reversible reaction?
the products of the reaction can react to make the original reactants
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what is a reversible reaction?
If the products of a chemical reaction can react to produce the reactants, the reaction can go in both directions.
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what is the thermal decomposition of ammonium chloride?
ammonium chloride (arrows) ammonia+ hydrogen chloride
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## Other cards in this set

### Card 2

#### Front

when can we calculate empirical formulae?

#### Back

given the masses or percentage composition of elements present.

### Card 3

#### Front

what is the empirical formula?

#### Back ### Card 4

#### Front

what is the empirical formula used for?

#### Back ### Card 5

#### Front

how can we calculate the empirical formula of a compound from its percentage ratio of atoms?

#### Back 