The mole
Tutorial 4
Molar mass
Reminder
One mole of atoms are $ 6.023 \cdot 10^{23} $ atoms
One mole of molecules are $ 6.023 \cdot 10^{23} $ molecules
The atomic (molar) mass of an element:
The atomic (molar) mass of an element ($ M $) is the mass (in grams) of one mole of atoms of this element!
The atomic (molar) masses are found in the → periodic table
Molar mass of a substance:
The molar mass of a substance ($ M $) is the mass (in grams) of one mole of molecules or structural units of that substance!
The molar masses of substances are calculated by summing the atomic masses of the → periodic table .
Relationship between mass ($ m $ in g), molar mass $ M $ and number of moles $ n $
$ n $ $ = $ $ \frac{m}{M} $
Calculate the mass of $ 1.2 \cdot 10^{24} $ carbon atoms
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Complete please this question before moving on to the next one!
$n$ $=$ $\frac{1.2\cdot 10^{24}}{6.0\cdot 10^{23}}$ $=$ $2.0 \;mol$
$m$ $=$ $n\cdot M $ $=$ $2.0 \cdot 12.0$ $ = $ $24.0\;g$
