MOLES Flashcards
What is meant by relative atomic mass?
The weighted mean mass of an atom of an element relative to an atom of carbon-12 having a mass of exactly 12
What is meant by the term molecular mass?
The weighted average mass of a relative to an atom of carbon-12 having a mass of exactly 12 units.
What is meant by the term relative atomic mass?
The mass of an atom of an isotope on a scale relative to an atom of carbon-12 having a mass of exactly 12 units.
What is meant by relative formula mass?
The weighted average of the masses of the formula units relative to an atom of carbon-12 having a mass of exactly 12 units.
What is meant my the term amount of substance?
- It is measured in moles
- Avogadro’s constant
- Measures the number of atoms in a substance.
Avogadro’s constant
6.02 x 10^23
No. of atoms per mole of a substance
Define the mole
The amount of any substance containing as many particles as there are carbon atoms in exactly 12g of carbon-12
How can the mass spectrum tell us the relative atomic mass?
Peak with the highest m/z value (molecular ion peak) due to the whole molecule after one e- has been knocked off.
m/z value of m+ peak = molecular mass
What is meant by the term empirical formula?
The simplest whole no. ratio of atoms of each element present in the compound.
Define molecular formula
The actual no. of atoms of each element present in a compound.
What is meant by concentration?
Equation of concentration?
The amount of solute dissolved per dm^3 of solution.
n=cv
Equation of Molecular mass, moles?
n= m/Mr
Equation of volume of gas?
n= v/24
