Formulae, Equations and Amounts of Substance

Question 1

What is a mole?

Answer 1

a measurement which contains 6.022*10^23 particles - unit of measurement for substances

Question 2

What is the calculation for the number of particles in a substance?

Answer 2

no. particles = moles * L

Question 3

2 Key equations to calculate moles?

Answer 3

mass/RMM or concentration (mol/dm^-3)* volume (dm^3)

Question 4

What is the molar mass of a substance?

Answer 4

a substances mass in grams per mole ( g mol^-1)

Question 5

What is Relative atomic mass (RAM)?

Answer 5

The mean mass of an element relative to one twelfth of the mean mass of an atom of the carbon-12 isotope

Question 6

What is Relative molecular mass (RMM)?

Answer 6

The mean mass of a compound relative to one twelfth of the mean mass of an atom of the carbon-12 isotope

Question 7

What is the empirical formula?

Answer 7

The simplest whole number ratio of atoms of each element in a compound.

Question 8

What is the molecular formula?

Answer 8

The actual number of each atom in a molecule

Question 9

Equation for percentage yield?

Answer 9

%yield = (Experimental mass/ theoretical mass)*100

Question 10

What could a low percentage yield indicate?

Answer 10

an incomplete reaction or loss of product during purification

Question 11

Equation for atom economy?

Answer 11

%atom economy = (Rmm of desired product/total RMM of reactants )*100