# calculations

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• Created by: 14megan
• Created on: 09-06-19 12:45
what is the relative formula mass (Mr) of a compound?
the mass of all the elements in the compound added together.
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how do you work out the percentage mass?
total mass of the element/Mr of entire formula x 100
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how do you work out the percentage yield?
actual yield/theoretical yield x 100
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what is the empirical formula?
the simplest whole number ratio of atoms in a formula.
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what is the method of working out the empirical formula?
1.write down the elements. 2.write the masses/percentages given under each element. 3.divide these numbers by the atomic masses of the elements. 4.divide these anwers by the smallest answer you get. 5.write out the formula and simplify.
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how do you work out the mass?
moles x molar mass
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how do you work out the moles?
mass/molar mass
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how do you work out the molar mass?
mass/moles
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## Other cards in this set

### Card 2

#### Front

how do you work out the percentage mass?

#### Back

total mass of the element/Mr of entire formula x 100

### Card 3

#### Front

how do you work out the percentage yield?

### Card 4

#### Front

what is the empirical formula?

### Card 5

#### Front

what is the method of working out the empirical formula?