Moles Flashcards
(6 cards)
1
Q
What is relative atomic mass (Ar)?
A
The average mass of an atom of an element
2
Q
What is relative formula mass (Mr)?
A
The sum of the relative atomic masses of all atoms in a compound’s formula.
3
Q
How do you calculate moles from mass?
A
n= m/Mr
where
𝑛 is moles,
𝑚 is mass in grams, and
𝑀𝑟 is relative formula mass.
4
Q
How do you calculate moles in a solution?
A
n=c×V
where
𝑐 is concentration in moldm⁻³ and
𝑉 is volume in dm³.
5
Q
How do you determine an empirical formula using moles?
A
Calculate moles of each element from mass.
Divide all by the smallest mole value to get whole‑number ratios.
6
Q
How to calculate percentage yield?
A
yield=
theoretical amount / actual amount x 100
