mass
'no magic to the mole'
amount
molar mass
concentration
solution volume
gas volume
molar gas volume
Avogadro
constant, L
number of
entities, N
Now try the following question.
G3. THE NUMBER OF ENTITIES IN A GIVEN AMOUNT OF AN ELEMENT
The simplest types of calculation are facile, effectively requiring only knowledge of the value of the Avogadro constant (normally given) providing it is clear what elementary entity is involved.
While for elements we are normally dealing either with molecules or, in the case of the noble gases, atoms, be aware that, depending on how a question is worded, the problem may involve an awareness of the number of atoms in a molecule, the so-called atomicity.
In questions Q1. – Q6. which follow, the relationships N = n L & m = n M can now be used as necessary. But, firstly, study carefully the two worked examples: the first deals with free atoms; the second a molecular non-metal.
Since the context here is a noble gas, it can be argued that the additional stipulation of the
elementary entity (i.e., atoms) is superfluous detail.
Now attempt a similar problem, this time dealing with neon.
