Amount of Substance

Question 1

You can convert between number of particles and number of moles using what formula?

Answer 1

Number of particles = Number of moles x Avogadro’s constant

Question 2

Equation for moles:

Answer 2

Mass divided by Mr

Question 3

Calculation for concentration:

Answer 3

Moles divided by volume (dm^-3)

Question 4

What is the ideal gas equation?

Answer 4

pV=nRT
p= pressure
V= volume (m^3)
n= number of moles
R= gas constant (8.31JK^-1 mol^-1)
T= temperature (K)

Question 5

Definition of empirical formula:

Answer 5

The empirical formula gives the simplest whole number ratio is of atoms of each element in a compound.

Question 6

Definition of molecular formula:

Answer 6

The actual numbers of atoms of each element in a compound.

Question 7

Equation for calculating percentage yield:

Answer 7

Actual yield
———————— x 100
Theoretical yield

Question 8

Equation for percentage atom economy:

Answer 8

Molecular mass of desired product
————————————— x 100
Sum of molecular masses
of all reactants